Question about RTC

[ChrizTheAtomicTofu]

Hey all,Chriz here again!
Now I've realized that one of my RTCs has a much pale-looking/slightly transparent fins then the other one,Help!

I'm feeding them frozen bloodworms,and the water condition is fine,low nitrate/ammonia levels.So whats the problem?Is he stressed?Or its natural?o.o

 

[guywithbluepants]

Pics of pale looking one?

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