The electron’s color is in a state of superposition just like Shrödinger’s cat. It is all colors simultaneously until we interact with it in which case it usually turns out to be red with irritation at being disturbed :-)
Electrons emit light (photons) when they change valence state. This is physics. So it depends on the element and the state change.
I'm thinking that light comes from photons - which I think are are electromagnetic (EM) waves and not a physical particle. Substances only have colour because of what parts of the EM wave they absorb or reflect. That makes me think the electron, like most other particles, cannot actually have any colour. And because it is so small it cannot absorb or reflect any EM/photo that hits it.
This question was part of a job interview from a Director of Engineering I had just after I graduated. He told me some of his best answers - I'll post them after you give me your best answers.