mapping vrayfur

I am using vrayfur to create some…hair type stuff. The hair is 200mm long. How do I get the tips of the hair to be red (for example) and the rest of the hair to be blue?

I also want to vary the heights of the hair with a bitmap, but the ends still need to have the same coloured tips.

I think I’ve figured it out. Random clicking gets me a long way sometimes!!!