Here's why:
* Fish color is determined by their scales, pigments, and sometimes, the reflection of light. These factors don't change just because a fish is about to die.
* Color changes can occur due to stress or disease, but these changes aren't a reliable indicator of imminent death.
* Some fish have the ability to change color for camouflage or communication. This is a natural behavior, not related to dying.
So, fish remain the same color they were before they die.