Here's some harpies displaying the random texture settings. I'll point out a few simple things about it.
These harpies are generating 3 values. The first value is a linear colour structure, and it determines the colour of their hair as well as what colour to tint the wings. This way hair and wings are always the same colour. They are also generating a random face variable, and setting a texture based on that, and the same goes with the Body texture.
Check the attachment for the same system being shown on Neko.