Change color of hair across width - Horizontal value for hair

I've found no way to do this, so there it goes as a feature suggestion. The only thing I found was someone with a similar issue in stackexchange blender.stackexchange.com/questions/64515/cycles-hair-strand-uv-coordinate

Currently, in Cycles, you can change the color of individual hairs across its length with the intercept [1] value. It would be nice to have something similar for the width of ribbon hairs [2]

What about the UI? See [3]. As a value right below "Intercept" in the Hair Info node. The name could be different, to avoid confusion with with "thickness". Other possible name for it could be "U" while renaming the current intercept to "V".

What are the applications? You can make hairs fade to transparent on the sides (similar to a feature in B Internal with strand render) You can make textured hairs, like feathers or leafs without using billboards or object instancing...