what color(s) of scales is he gaining? :3

honestly I didnt really think about that when drawing (black and white saves me from making tough decisions like that lol) so its whatever color you think would look cool!

okay edit: second half first then his scale colors if he were an adult/maybe when he is older?
I wanna see more sexual dimorphism in species designs where the males are bright and colorful and the females are toned down (no less pretty, maybe really shiny and neutral toned blue-gray, perhaps with accents of red of their own but nothing as vivid as what testosterone grants). Perhaps the bright colors are sexually selected for and serve as health indicators too (dull scales = sick or hella old). Tho given this is a young mer (a teen likely?) I imagine maybe he has more of a juvenile coloring where there are hints of bright adult scales in patches (he is very healthy!) but mostly toned down blue-green scales that are kinda reflective :3
As for when he grows up: yellow fading into green then teal with stripes of crimson to bright orange at the sides! :3
oh oh! And his tail fin is seafoam teal w/ lime green veins and tipped in red!

I'll do whatever he wants me to do for him to answer yes to that question :3

I LOVE THIS, FISH DESIGNS ARE THE COOLEST!!!