@matrix @LukeAlmighty
It's not unreasonable, you can see aquatic creatures having darker shades to blend in with the dark surroundings. But the issue is, it's kinda hard to argue this for Ariel, when her tail is a bright, iridescent green. I honestly considered this myself. Sun protection isn't by far the only reason why an animal would adopt darker colors. But the camouflage argument drops the second you realize Ariel is as inconspicuous as a peacock.