Hair Coloring and Heat

Woman with red hair and a clock
Q: When heat is used to accelerate the coloring processes how should the time be adjusted? I know without heat it should be about 25 minutes so with heat is it like 15 minutes heat and 5 minutes cool down?
Also I have naturally light brown hair and super dark brown/black eyebrows, and I recently dyed my hair a dark red color. A lot of people have said I need to make my eyebrows match, but a stylist friend of mine said it would be a bad idea, because it fades so fast and dark red isn't natural to begin with so matching eyebrows would be strange. What do you recommend with dark red hair and black eyebrows?

A: First of all, the timing of hair coloring and bleaching is primarily affected by the strength of the developer and bleaching agent used, and the porosity/resistance level of the hair. Heat is generally used when the hair proves to be more resistant to color and bleaching, or to make the lightening process faster with darker hair.
It’s not possible to exactly quantify the timing with or without heat in a color/bleaching process. An experienced hair colorist can often gauge the timing intuitively, but that is only because he or she would have performed the process many times before. If you plan to use heat to help process a service you’ve performed on yourself before, you need to watch the hair closely.
As for the idea of coloring your eyebrows, a good rule of thumb is to keep the color of your eyebrows and hair within a few shades of each other. It isn’t necessary for the hair and eyebrow color to match exactly. In fact, most people’s brow color and hair color don’t match.
If you feel that the color of your brows is too dark compared to your hair color, you can use a red based color with some lifting action to add a reddish tone to your brows. Just remember to be careful using any color around the eyes.
Your stylist friend is correct in that dark red hair isn’t natural, but I know that many clients of my own are not comfortable with their color service – particularly when dealing with red hair color applications – unless we treat their eyebrows as well, to keep the colors in the same range.
Photo: Elnur/Shutterstock
See also:
Hair coloring and bleaching
How to color your eyebrows
Tips for redheads
Home hair color kits and timing