When coloring hair
poor gray coverage
Poor gray coverage often happens because the texture of gray hair is coarse or resistant, and needs more time to absorb. Once you know this, you can get great gray coverage by changing the application process.
Apply color first to the areas your hair has the most gray, usually the front hairline and natural part in your hair. Then apply to the remaining hair, going back again at the end to the resistant areas. Make sure you saturate your hair with color. It may even be beneficial to add a second tube of color. Use a wide tooth comb or your fingers to massage the color through the hair to ensure each strand is fully saturated. During the process time, use a color cap to trap in heat, and give hair a little more time—up to 15 extra minutes—to absorb the color.
problem: Too Dark
Too dark hair color happens if you color too often from roots to ends. That is, permanent hair color works by opening the hair cuticle and depositing artificial color. If you repeat this process all over, it becomes more difficult to keep the hair cuticle closed toward the older mid-length and ends of the hair. The color will absorb more efficiently into the cortex of the mid-length and ends, eventually building up and appearing denser, darker and duller because the raised cuticle doesn't reflect light.
The best way to prevent this is by only coloring roots after the initial application of a new color or shade. That way, you will avoid reprocessing hair that has already been colored. This will also help prevent fading, as repeatedly lifting the cuticle to add color can cause hair to become more porous, allowing it to absorb color quicker, but at the same time, it won't be able to hold color as long, leading to fading. Rather than repeatedly color from roots to ends, consider using a gloss refresh color-treated hair and add shine.
problem: Hot Roots
Hot Roots is a stylist term to explain what happens when the roots of your hair are a noticeably warmer, lighter color than the rest of your hair. This happens for one of two reasons:
When you try to color previously-colored hair a lighter color. The natural hair closest to the scalp lifts while the already-colored hair doesn't.
Avoid this mistake by choosing a color the same level or darker than your existing color-treated hair, and apply to the roots only.
When you try to lighten natural hair all over. The hair closest to the head lifts lighter and faster than the rest of your hair due to the heat coming off your scalp.
Avoid this by applying the lighter color to the ends first, leaving the roots alone for the first 20 minutes, then mixing fresh color and applying to the roots only before massaging it throughout the whole head.