This is GT500's work. Send him some thanks and Kudos!
I created a PSD where I added the names of the hair colors in a layer on top of the texture for the regular Vivid Hair Colors (1.1).
It's a bit hard to read due to the size of the texture, however it should still be helpful.
Obviously you can substitute any of the versions of Vivid Hair Colors (or any other hair color texture) simply by copying it over the texture in the bottom layer, and even free software such as GIMP can toggle the top layer on and off so you can show/hide the names of the hair colors.
Edit: If you're using GIMP, make sure to delete the top layer (with the names) before saving as DDS. I've noticed in more recent versions that it will save all layers, visible or not, in the DDS file, so only allow it a single layer before saving and have it generate its own mipmaps just to be on the safe side.