Personally, my opinion is if the RGB LED lights is starting to go out or fading that is not important as long as the CPU Cooler continues to keep the processor cool.
Cosmetic reasons (LED Lights on the CPU Cooler) doesn't affect how the CPU Cooler maintains the processor cool.
Yes Hardware RGB LED Lights looks nice but not essential in a PC.
You can open a AMD Warranty Request and see if AMD will replace it under Warranty if it is less than 3 years old.