originally on lights, but i had more troubles with the hair, and the shadows, and their colours.
im trying to draw these now from colours. and the reference has purple shadows, magenta midtones caused probably by a magenta lamp standing somewhere, and yellow highlights, and it wasnt easy to follow while painting, and not only colouring in the end. plus the photo has wowsomany light sources creating shadows wowsomany places with wow opacities : D these practices are good. i obviously need them.