Using vertex colors to color hair in Cycles

I got a question related to my WeightLifter Addon asking whether is was possible to use the addon to control hair particles. The addon itself does of course not control any particles but the vertex groups and vertex colors it creates can be used by any particle system to control the distribution and coloring of the the particles or hairs strands as shown in this example:

For this image WeightLifter was used to create a vertex group with more weight on horizontal surface:

Then this vertex group was used to control the distribution of the hairs by selecting the gruop in the particle system settings:

In the same manner WeightLifter was used to create vertex colors that change colors from left to right:

A Cycles material was then created to use these vertex colors (via the Attribute node) to color the hairs