Let me first say that I am not a professional hairstylist. I have a lot of experience coloring my own hair, so I've figured some of this over time and by talking to stylists. What I know for certain, though, is that the number (20 or 30) refers to the amount (ie: volume/percentage) of peroxide in the product (ie: developer). The 30 is used when hair is being dyed to a shade that is more than maybe 2 shades lighter than your current color. The 30 is sometimes also used to be sure to avoid brassiness, as brassiness can be a result of the color not 'moving past' the orange zone on its way from darker to lighter. Granted, if you're dying your hair red, brassiness might not be as noticeable. To be honest, though, most people end up having to tone the brass out of their hair by using a toner or a demipermanent color in place of a toner. Wella makes good toners (which you would use with a volume 10 developer -but...be careful if your roots have grown in because, unless you dye the roots to match the rest of your hair, the toner will leave the roots a different and brassier color than the rest). If you end up needing to tone out brassiness, sometimes a demipermanent color rather than a toner is better (for the demipermanent be SURE to use Wella's developer made specifically for their demipermanent colors). Depending on how light you've dyed your hair, you may be able to use demipermanent color 6, 7, 8, etc. followed by the letter "A" for ashy. If someone were toning very blond hair, for example, they'd choose 10. If you were toning a mid-brown color, you'd chose a lower number like maybe 7. In terms of Natural African American hair, you are starting with hair that is not already damaged from other chemical treatments, so that's a plus in terms of the impact of the peroxide. However, 30 volume will be more drying, due to being harsher (because it has more peroxide). The decision between a 20 volume and a 30 volume has more to do with how may shades you're "lifting" (lightening) your hair and how dark it is to being with. The curliness or coarseness of hair is only an issue if you're concerned with causing more damage and/or drying out the hair more. I'm caucasian, but do have curly hair - it's harder for the natural oils of the scalp to make their way down a textured hair shaft (and with curls, everybody knows we don't brush or they get frizzy, while straight-haired people brush, thereby redistributing oils from the scalp area to the shaft of the hair), so I always deep condition after coloring. I would say this: If you are lightening your hair by more than 2 shades, you may want to wait until salons reopen, if that's an issue. If, like me, you're always looking to save a buck (coronavirus or not!), you may want to call a couple of hair color 'hotlines' - those numbers can be googled, or you can just find them on the back of a box of L'Oreal hair color, Redken, etc. You don't want to destroy your hair or have it break off.
Date published: 2020-06-16