Tricks on how to color the hairline all the way to the beginning of the knot on a lacebase. Suggestions?

If you got a thin, fine toothed comb and slid it into the base of the hairs, it would act as a protector to the base.
Also using a small mascara brush would allow you to get as close to the base as possible and limit the amount of dye you were applying, so it would be less likely to drip.

I don´t get the color all the way down. Is there another way?