Hmm...Is this his default coloration?

Well that's what he's gonna look like when he isn't using any abilities, but he's gonna have to glow some kind of color when he is.

Purple! It’s looks good on Goji…

Then I'd go for an orange glow in contrast with his maroon scales.

Will he be glowing on the eyes, mouth, and dorsals, or all over?

He doesn't have a specific skin color yet-

Orange would be sick

Blue is my favorite but I actually might be leaning towards orange or red.

If you choose 2 colors that's what the mixed button is there for

So far blue orange and mixed is tied