hows and whys of rainbow hair coloration: how to dye your hair like an engineer
Not the philosophical hows and whys, of course, but the procedural ones. This radiant violet mane ain’t natural; I consumed many hours of DIY hair blogs to distill my current repository of cumulative knowledge about how to properly fry your hair. I’ve re-purpled myself often enough that it’s now a relatively casual and painless process, but for the uninitiated, I’m decompiling it out of my head here so you need not replicate the effort of navigating the conflicting and varied opinions of the blogosphere.
All the blogs I could find only described the number of minutes and amount of bleach used for the exact hair on the author’s head, which was massively infuriating. As usual, my tragic flaw was my overwhelming compulsion to un-silo knowledge and underlying principles at cost of sleeping or eating, so I was determined to compile enough generalized information so that more people could not only figure out what steps they needed to take to get the colorful results they want on their hair, but also understand what’s happening at each step so that they can debug mid-process.
CAVEAT: This post is specific to straight/wavy hair and will be most useful for thick, straight/wavy Asian hair because that is the kind I have. I got tired after digging up all of the information I could find for type 1-2 hair, and did not go the extra mile to dig up specific information on curly hair, since my hair is not qualified to verify any of it.If you have curly hair, a lot of the generalized information will still be useful, but you probably want to look up specific tips from fellow curly folks, start with a test streak, and proceed cautiously, as curly hair is much more porous and therefore damage-prone than straight/wavy hair. Common advice for curly hair is that you will want to do significantly more deep conditioning than you would on straight/wavy hair.
While you still have the potential to become a DIY hair horror story if you get impatient and try to instantaneously become platinum blonde in one sitting, you don't need to be afraid if you are willing to start slow, take more time to understand your hair, and maybe not achieve your perfect color on the very first try.
* As a general rule, I only do irreversible things once I have a fairly complete understanding of how they work. If you do not operate the same way, feel free to skip straight to Bleaching: How for the cut-and-dry instructions.
Hair salons will fill your ears with needless worries about DIYing it. If you can be mindful about checking a stopwatch and you are patient enough to learn your hair's preferences, fear not; coloring your hair at home is actually super easy and averages around $4 per monthly re-dye for lazy people like me, plus $3-6 per bleach session.You’re not even saving time by paying to get your hair done since your body has to be present the whole time :)(On the other hand, if you do not wish to invest this mindfulness and patience, and your desire is to pour on the strengthiest bleach to rush to the finish line, then you are much better off going to a salon.)
Bleaching: Why
Like most physical pigmentation processes, hair coloration is subtractive, like mixing paint or coloring over markers with other markers. Thus why you need to bleach so light to dye unnatural colors, even if you want them to come out dark; purple over brown is basically dark brown. If you try to put an unnatural color like blue/green/purple over anything darker than light blonde, your color won’t show up well without direct sunlight.
Even if you’re already very light-haired, you’ll still want to bleach a little because porosity also helps with dye retention. Basically, if your hair strands are porous, dye can stick in there, and if your hair is super smooth and healthy, it’s more difficult for dye to deposit. Obviously, too much porosity is bad when your hair becomes so ragged it breaks off. (If your hair is naturally very porous, you will want to be more careful here.)
1. Bleach addresses both of these needs by simultaneously decolorizing and fucking up your hair. To apply it, you mix a bleaching powder with an oxidizing agent, called a developer. (Lest you should mistakenly think to substitute hydrogen peroxide, know that the maximum strength developer used on hair is only 12% hydrogen peroxide, and any more may literally make your hair fall out.) This is a surprisingly exothermic process which will be active for around an hour or until you wash it off. If you haven’t done this before, continuously check your bleached bits to see how light they’ve gotten, and err on the less-bleachy side until you figure out the right duration for your hair.
After bleaching, there are typically orangey-yellow (“brassy”) tones left behind. This is due to some combination of your natural keratin coloration and remaining hair pigment, and it’s another reason you must lift so much color to dye your hair rainbow. Your hair color isn’t turning into a lighter version of itself in HSV space; it’s more analogous to a change in RGB space.
In other words, bleaching dark brown hair doesn’t turn it into light brown hair — it removes a color component that was previously canceling out or concealing an orange color.
Asian hair is particularly notorious for being a shocking orange underneath, and unfortunately, I can’t dye myself purple at this stage because purple plus orange makes brown. So even though I want to end up at a relatively dark shade of purple, I need to bleach myself all the way to blonde before the purple will be cleanly visible.
If you want to end up at red, orange, or even green, you can take it a lot easier. For example, my friend with green hair gets there by bleaching to medium yellow and then applying turquoise over it. White will be the trickiest, with silver a close second.
The reason to wrap hair in foil while bleaching is that it retains heat and moisture, and heat accelerates oxidation. I don’t have citations for whether the moisture is also a critical factor because hair bloggers don’t write about reasons why things work, but I can empirically tell you that without foil, an hour of bleaching merely lightens my hair from black to darkest brown. At a minimum, I would guess the moisture helps with evenness via facilitation of particle mobility.
Bleaching your hair will change its texture! My natural hair is stick-straight and extremely smooth, so it becomes wavy after bleaching because damaged hair has more texture (and, by corollary, volume) than super-smooth hair. Curly-haired internet people report that bleaching changes their curl pattern. Conversely, if your hair is very curly, it’s possible that bleaching may loosen your curl. When in doubt, Google a hair blogger with the same “hair type” as you.
2. (optional) Double processing is when you follow up bleach with toner to go platinum blonde. Toner deposits violet which, when mixed with developer, counters light yellow and cancels to get hair that looks white. If you’re not on a quest to make your hair silver, white, or some super light pastel, you don’t need to worry about toner.
If you do want to have white/silver hair: don’t bother using toner until you are already as blonde as you can possibly go. Toner is subtle enough that it won’t really make a difference if you are still brassy yellow.
Timing
The amount of time you need to bleach to get to blonde varies drastically by original color and hair thickness. My friends have reported ranges from 20–30 minutes for thin light hair to two hours for thick Asian hair (we gaze enviously upon the light-tressed who casually color their roots on a whim), so increment carefully and visually check often until you reach your desired result.
Personally, I’m completely okay with getting a slightly uneven result instead of bleaching all the way to a blank canvas. The remaining base color mutes the purple a little, and my goal is to look like my hair is just naturally purple (whatever that means).
I polled some colorfully-haired pals to get more heuristics on how hard they have to bleach to get blonde/damaged enough to dye their hair rainbow colors. While this is by no means a statistically meaningful sample, it might at least help provide a starting point if you have never done this before.I would recommend starting at the mildest bleach strength/time that seems reasonable for your hair type, and then carefully working your way up once you see the results.[developer strength, active bleach time (original hair color)]East Asian
40 vol, 120 min (from black)
40 vol, 120 min (from black)
40 vol, 120 min (from dark brown)
40 vol, 60 min (from black)
20 vol, 50 min (from dark brown)South Asian
40 vol, 100 min (from black)Caucasian + East/South Asian
30 vol, 80 min (from dark brown)
30 vol, 60 min (from dark brown)Caucasian
20 vol, <= 20 min (from blonde)
20 vol, 30 min (from brown)
30 vol, 30 min (from brown)
30 vol, 40 min (from brown)
30 vol, 50 min (from light brown)
40 vol, <= 20 min (from dark brown)(Apologies for the terrible lack of diversity in this poll; although type III/IVs can totally rock colorful hair, none of my type III/IV friends DIY bleach their hair for some reason, maybe because curly hair is already high maintenance enough as is. Speaking personally, I am desperate for more fun hair because straight hair just has less styling options than curly hair.)Here are some numbers I dug up from some online curly tutorials:
- [NaturalCurlEnvy 3c/4a] 20 vol, 30-60 min
- [OffbeatLook] 35 vol, 14 min, protein treatment
Once “activated” by mixing with developer, bleach will only continue oxidizing for about an hour. So if you need over an hour, you will have to do this in two separate bleach-wash cycles.
Internet wisdom claims that multiple bleaching sessions should be spaced by at least a week so your hair has time to “rest”. I don’t know what that means since hair is dead and has no intrinsic repair mechanisms and my hair is apparently indestructible, but I think you’re supposed to use the time to apply external repair mechanisms, like protein treatments.
At the extreme end of the spectrum, I use 40 volume developer in two back-to-back hour-long sessions. This is not recommended except for the thickest, blackest, strongest, healthiest hair, and even then you should definitely start out lower and work your way up to be sure. I started my hair journey with 20 vol (which did literally nothing for me) before working my way up the bleach intensity ladder.I currently do my two bleaching sessions on the same day because I’ve discovered my natural hair is basically indestructible, but I reached this conclusion through a year of incremental testing — I started out spacing my bleaches by a week and conditioning heavily with many protein treatments, then progressively decreased the spacing once I knew my hair wasn’t going to fall out. It’s common to find reports from people who fried all the hair off their head by going straight for the high volume bleach!! Start slow! It’s less of a pain to have funny-looking brassy hair for one week than to regrow all of your hair.
Roots
Because the bleaching reaction is accelerated by heat, bleach will work faster near your scalp due to the heat from your body. If you bleach it all in one pass down to the roots, your roots will appear noticeably lighter than the rest of your hair.
In addition, bleach is damaging to your skin. It might not be a big deal if you only need 20 minutes to bleach your hair, but if you’re like me and need two hours, it will be very painful and flaky. Some people recommend rubbing coconut oil into your scalp before bleaching to help moisturize and protect the skin.
I don’t personally bleach all the way down to my roots, but if you want to: leave about half an inch of roots unbleached on your first pass, and put the bleach into your roots when you have 20 minutes (or half your total bleach time, if less) to go. This will help protect your skin and even out the color difference from the heat of your body.
Nervous? That’s ok
If your hair is naturally porous, fine, dry, light-colored, or damaged in any way — or if you’re just nervous for some other reason — there are many ways to take it slow and safe.
- Bleach just one streak, and isolate the rest of your hair using a shower cap
- Skip the roots
- Start with 20 volume developer
- Check the color every 10 minutes
Addendum: When you redo your roots, minimize any overlap with the already-bleached parts of your hair. Underneath the dye, it is still as porous and blonde as when you last bleached it, so you don't want to damage it extra.Bleaching: How
Quest inventory
- Bleaching powder: L’Oreal Quick Blue ($15 / 16 oz tub, or $5 / 1oz packet)
(People with thin, fine, or short hair may be able to get away with 1–2 packets. I need about 3–4oz to do my whole head, so I buy bleach by the bucket.) - Developer: L’Oreal Oreor Creme Developer ($6–8 / 16oz)
- Toner (optional): Wella Color Charm — White Lady ($5 / 1.4oz)
(…yes, they actually named it “White Lady” -_-) - Plastic cup+utensil to mix the bleach
(don’t use metal; it will react) - Gloves, aluminum foil, shower cap or plastic wrap, and a sacrificial T-shirt and towel
- Rags or paper towels to quickly wipe up the splats of chemicals and dye that you will inevitably fling all over the bathroom no matter how careful you are
* I can't specifically advocate for these brands over any other brands — they work great for me, but they’re just whatever I found that was inexpensive and well reviewed.Developer comes in different strengths (peroxide concentrations).
Use cases:
10 volume - For very mild color lift, such as if you’re naturally light blonde and just need to open your hair’s pores.
20 volume - Standard prep for American salons or thin hair.
30 volume - For darker or thicker hair.
40 volume - For very thick, strong, black-colored hair (such as East/South Asian). May literally disintegrate fine hair.
What to actually do
Don your designated bleach shirt and gloves. Loosely section your hair into 4–10 manageable small handfuls which bleach can easily be combed flat through (I just do this on the fly). Mix the bleach and developer according to instructions on the packaging. Thoroughly massage the mixture through each section, wrapping them in foil as you go until you look like some kind of cyberpunk space medusa. If you have as much hair as me, it can take half an hour to get through all of it, so do some bilaterally symmetric pathfinding (alternate sides) to avoid noticeable color differences.
If you don’t know how long to wait, continuously peek at your hair every 10 minutes to see what color it’s turned. Like bread fresh from the oven, it will continue to bake a little bit after you wash out the bleach, so it’s fine to err on the cautious side and wash once you’re close to your desired shade.
Once you have attained a satisfactory lightness, wash with shampoo and use an old towel you don’t care about. This is now your designated bleach towel because it will be totally ruined for anything else forever.
* Manually petting bleach downward with your fingers results in a relatively soft line. You will get a more obvious, harsh-edged growth line that necessitates frequent touch-ups if you use a brush applicator or bleach all the way down to your roots. Put bleach on your (gloved) fingers and grab semi-random chunks, then pull the bleach downward through the chunks.* If you want, you can gradient your bleach instead of bleaching all the way down to the roots so that it looks more natural as it grows out. Since bleach is time sensitive, you can gradient by simply saving a few bleach-free inches on the first pass and then doing a second pass about 20 minutes before time is up. It also looks nice to variegate the bleach line with some highlights that go down to the roots.(I no longer gradient, since I don't like the bleach boundary to show up brassy orange as my purple fades.)
Dyeing
Great — the hellscape of hair bleaching has run its foul course and your hair is now a horrible bird’s nest made of limp yellow straw. Now what?
1. Permanent dyeing is an oxidative process and must be used with developer, making it damaging to your hair. I don’t know much about permanent dyes except that they’re a sort of combination process which simultaneously bleaches while depositing color. Many big brand name dyes, hair salon dyes, or drugstore box dyes will be of this type.
2. Demi-permanent dye deposits color (on top of already-bleached hair) that tends to wash out in 2–8 weeks. Many of them double as conditioner, and actually make your hair feel healthier. All the rainbow-colored dyes I have personally used are non-damaging to leave in, but obviously, check first if you’re not sure.
Applying a non-damaging dye is far more relaxing than attempting to bleach East Asian hair. Just put it on your hair, put that hair in a plastic bag, wait at least an hour (you can even wait overnight for extra potency), and then take a cold shower until the water runs clear. I use gloves when showering to prevent my hands from getting stained purple.
Congratulations! You are now colorful and your hair has resumed a semblance of its former luscious glory!
If you’re dyeing all the way down to your roots, you will leak dye all over your scalp. Applying Vaseline around the edges beforehand is a tried and true method to avoid staining your hairline.
Brands I’ve tried
- Special Effects (fades aesthetically)
- Pravana ChromaSilk (extremely potent; bleeds on everything)
- Arctic Fox (doesn’t seem to bleed too much)
- La Riche Directions
- Manic Panic (fades quickly for me; YMMV)
Reputable & widely-recommended brands I haven’t personally tried
- Goldwell
- Jerome Russell Punky Colour
- Joico
Some of these dyes at full strength (particularly Special Effects and Pravana) are so oversaturated with color that they continue to bleed out on your clothes and pillows for weeks. My friend who uses the same dye as me, but undiluted, was once asked if he had used his pillow to murder a Smurf. To mitigate such unwholesome misunderstandings (and ruining of shirts), you can dilute your dye with any cheap conditioner until the dye looks roughly twice as dark as the hair color you want to end up with. Pravana violet looks exactly the same on me when I dilute it to 1/3 strength. Bonus: you have now saved a multiplicative factor of money and your post-dye shower will go faster.
I currently use Pravana diluted to 1/3 strength, and touch it up every 3-4 weeks when the top of my head has faded. Cost comes out to $2–3 per application, since the underlayers fade slower and I don’t need to redo my entire head every time.Undiluted, it lasts around 6 weeks on my friends (several of them started using my previously-rare color after I published this blog post, so now I am less unique).I used to use Special Effects diluted to 1/2 strength, which faded to different colors on me.* Having trouble selecting your perfect color? Haircrazy is a great community resource on different dyes, with lots of photos of how dyes come out on different people's hair.
p.s. Pastel dyes are a scam; they are just diluted. Save your money and mix a dollop of normal dye into cheap conditioner to get pastel.
Fading
Touching up your dye is far easier than re-bleaching, if you don’t mind roots — all you need is an hour or so of letting dye soak into your head (go read a book, and refrain from vigorously hugging anyone wearing white clothes) followed by a normal shower.
I touch up the faded top layers of my hair every 3–4 weeks, which is a fairly typical duration for most colors to stay vivid. Certain dyes can last on me for several months (I’m looking at you, Special Effects magenta), while very delicate pastels may barely last two weeks.
Color composition and your base color factor into how your dye will fade. You're probably still a little yellow-toned underneath, so a faded blue will look green. When the blue component of purple fades, it leaves magenta behind. Remember that dye is subtractive and combining two complementary colors will cancel out to some shade of brown, so you can’t switch directly from green to red. I know some people who switch by rotating around the color wheel each re-dye — like going from green to blue to purple to magenta to red.
If you do want to intentionally fade out your hair in order to dye it a completely different color, a hair stylist once told me that baby shampoo is a good method.DO NOT rebleach for the purpose of getting dye out. Only rebleach if you didn't bleach your base color light enough the first time, and your hair feels healthy enough to take it.
Things that will make your hair fade faster
- swimming
- hot showers
- shampoo
- sunlight/UV
- everything good in life so no use worrying about it
I've been in the no-shampoo camp for most of my life, which incidentally helps with color retention.Aftercare
The dye should have helped make your hair feel less like someone tried to salvage straw from a forest fire, but it’s probably still much less healthy than it was before you bleached the hell out of it. You will probably want to mitigate some of the damage with protein treatments at this stage.
Dainty Squid has meticulously run her hair through the whole rainbow of possibilities and writes some of the most thorough blog posts I’ve found about vibrant hair color maintenance; here’s her hair master post and excellent color maintenance tips.
Everyone’s aftercare routine will be different. My hair is so thick and strong that apparently even bleaching it with 40vol for two hours in a row and not owning conditioner couldn’t destroy it, so I am not the ideal person to ask about aftercare. I follow up each bleach+dye with a few days of Redken Extreme Anti-Snap Treatment, which seems to reverse my post-bleaching limpness. Black Girl Long Hair’s whipped shea butter is good for split ends and general dryness.
I polled my friends for additional secondhand product recommendations (the efficacy of which I can neither directly confirm nor deny): Joico Color Therapy Luster Lock, Bumble & Bumble hair oil, Pravana Chromasilk hair sealer, Olaplex, Aphogee protein treatment, coconut oil, argan oil, castor oil, shea butter, apple cider vinegar.
Enjoy your new bond with strangers with the same color of hair as you; nod wistfully at them, knowing you truly understand the sacrifices you made to get there.
Also, say goodbye to any white shirts you have, because you probably can’t wear them without permanently staining the neckline any more.
