Dom's tail was like that when we got her. These are all wild-caught. You can see some dark areas on Sub as well, probably old scars.
The females range from brown to olive green, and sometimes fire up to a brighter green.
The males range from black/dark grey to brilliant eye-popping blue. Occasionally juvenile or subordinate males are mistaken for females, as they can be more olive green when not fired up.
Here's Dom all fired up to the maximum (sorry for poor picture qualities).
You can see she has inflated her throat, and is showing off.