In this month’s Ask a Colorist feature, we’re breaking down everything you need to know about lightening hair after dying it—because lightening uncolored hair is one thing, but lightening already-colored hair is another.
Every day, we receive tons of questions about lightening colored hair—Can I do it by myself? Can I go from black to blonde all at once? What’s a “lifter” anyways? We’re here to give you our expert insight into lightening hair that’s already been colored.
01 CAN I LIGHTEN ALREADY-COLORED HAIR AT HOME WITH HAIR DYE?
Generally speaking, hair dye won’t lighten previously-colored hair. Why? Because it’s not designed to! Hair dye is created to simply add color to your hair, not to lighten or remove color. Think of it this way: Once you add color to your hair, the hair molecule becomes filled up with color. To change your color, you have to let the molecule shrink over time, aka, let your color fade before you “fill it back up” with a different color. It’s like eating a big meal—when you are full, there is simply no space left. Now, if you want to lighten your previously-colored hair, there is added complexity to consider and understand.
To lighten your hair, not only do you have to wait until the hair molecules shrink, but depending on how light you’re looking to go, you may also need to “strip” away your hair undertone. What’s an undertone? Each hair follicle is essentially made up of two layers. The first layer is your underlying pigment, which is the tone at the base of your hair. The second layer is your hair shade, for example, black, brunette, or blonde. Together, both layers create your “overall color.” Your undertone makes all the difference in your results. More often than not, when going lighter you have to strip your undertone to brighten it up, and then add your desired shade (aka hair dye) on top!
02 WHAT’S THE BEST WAY TO LIGHTEN ALREADY-COLORED HAIR?
To lighten previously-colored hair, we recommend you do one of two options. The first option is to use a strong lifter—treatments that have a volume of ingredients like ammonia, peroxide, bleach, or alternative chemicals that clear the hair molecules of color. Then after you have lifted your hair, you can apply your desired color. The upside of option one? It’s a fairly quick process, depending on how much you wish to lighten and tone. The downside? Strong lifters that significantly lighten hair are pretty invasive treatments that can cause damage and thinning, and it’s a pretty tough process to pull off at home, so we advise you get it done at a salon. (Note that low-peroxide containing lighteners can be used safely at home to highlight hair, but is not advised for getting and maintaining an overall lightened shade.)
The second option is to wait 8-10 weeks after you initially dyed your hair, to allow time for your hair color to fade and your hair dye molecules to shrink. Once your hair color has faded, you can then dye your hair at home. With that said, after allowing the time for your hair color to fade, at-home hair color typically only allows 1-2 shades lighter. If you are looking to dramatically lighten your hair, say, 3-5 shades, see option one (bleaching).
If you’ve chosen to go with option two, there are things you can do in the meanwhile to maintain your roots or give your hair a lightened feel. The first thing you can do is use a root coverage spray. This is a great option for people who are waiting for their color to fade but still need root coverage for grays and regrowth. You can also apply highlights at home, to give your hair a sunkissed, lightened look while you’re waiting to go full throttle with an all-over lightened color. Need help deciding which option is best for you?