please forgive,,, my reuse of old lineart…

in case u can’t see, the layer mode i use for the glow and multicoloured flecks is luminosity or, in my case, “-¾^ã”. each separate component goes on a new layer - this way, you can make your crystal whatever colour you like by just recolouring each bit (ideal for adoptables!), the reason i use black for the flecks is to make them easier to see while drawing em.

this colour is rust btw