Help with lighting and colour on a drawing?

[Gravy]

Not looking for criticism on the line work, this is me trying to improve my lighting and colour.

Anyway, here's the image: https://twitter.com/SincereSandwich/stat...80/photo/1

I'm a bit stuck, especially on the forehead, I don't know where to add light. I've decided for the light source to be in front of the character (above their eyeline so it's kinda looking down on it). Also, the colours look a bit dodgy, I don't know though, I dunno if being colourblind really affects my judgement in that aspect.

Anyway, help would be much appreciated
Also, ignore the incompleteness of it, I've yet to do most of it.

[Starrysaber19]

For the forehead moving the highlighted part a little higher and making the 2 highlights come closer towards each other, should do the trick, for the chin the highlights put them lower, closer, smaller.
The color of the mustache is ok, the color of the skin is a little yellow kinda like potato, I dunno if that was on purpose or not.
Good luck