[JeVousDefie]

I've seen a few posts around asking about bettas going from a dark color to a lighter one when stressed, or even a post about someone's white betta getting red streaks...but I haven't quite found this anywhere. If it already exists, I apologize for the extra questioning, please redirect me there. I purchased a female at Petsmart a few days ago. She was not doing very well. But at petsmart and for the first two days, she was a very white color (not like a sickly pale, but like white). Last Night, I noticed that she looked almost green. Assuming I was just seeing things because I was tired, I went to bed. Today, I noticed it was a lot different. She has a dark greyish green tint to her fins, and her face is like a dark grey, and her body has some grey spots. Almost like she's becoming a much darker color. Is this somehow normal?

 

[Aqua Aurora]

A photo would help confirm but it may simply be a marble betta, forum member lilnaugrim can go into better detail on marble bettas but short version they can change color very unpredictable, sometimes rapidly sometimes slowly. I have 2 marbles, one marbled drastically from the time I bought him online to when he arrived at my home i almost thought it was a different fish but he has specific defects/characteristics unique to him (went from a blue black to multiple hues of blue in his body). The other has marbled slowly but noticeably (white with a tiny bit of red in fins to more and more red in the fins).
Another possibility is different in lighting or orientation of fish in relation to light can make them appear to be different colors. I have a blue and 'rustic' red hues boy that can look purple or even pink depending on lighting and his placement. Another boy might look blue or green from lighting.

 

[themamaj]

When I brought my Blizzard home he was solid white with a little celophane on tips. Since home in heated tank he has marbled red tint coming out on his fins. Not unusual for them to color up once home but sounds like you are a lucky one with a marble! They are most facinating to watch change!would love to see a picture of your guy