Betta female turning white

HI all, wondering if anyone is familiar with what might be going on here. I have a female betta , part of a sorority in a 20 gallon tank with 5 other girls. She has always been light , koi colored , but the past few weeks I have noticed her slowly losing the reddish/orange color on her head, and one area on her fin. It doesn’t look fuzzy or patchy, there’s no bumps, and it’s not rusty colored like velvet. She’s just turning whiter and whiter?! I read about neon tetra disease but it doesn’t really seem to be this either as she is acting competely normal. One of my dark females had something similar a few months ago but it wasn’t on her face, it was mostly her body that turned lighter in bands. Could this be her version of breeding stripes? Pics attached - from today and a few months ago.

 

Could be marbling, but usually marbling ends in a darker color but I have a betta that marbled a little white.

Is it acting off?

What are the water parameters?

 

She’s not acting off at all, seems just as feisty, eating enthusiastically with all the rest of them. Just tested and looks like nitrate is a little higher than normal, but they are due to get a PWC tonight so I’m sure that will lower it back to normal...

ammonia: 0
Nitrite: 0
Nitrate: between 10-20ppm

 

Ok, seems fine for now IMO. Nitrates look perfectly fine too.

 

Just her colouring. Kois are marbles, and marbles change colour over time. Usually darker, but lighter can happen too

 

Looks like just a color change. I have a female betta who is doing the opposite. She was all white and has now started to get some color around her head.

 

Thank you all for reassuring me!! I’m still going to be sure to keep a close few on her just in case - I love my betta girls so much! So much more active than the males without the super long fins!

 

colouring if I had to guess
just be careful to make sure you don't mistake it for a fungus if she ever gets one

btw your blue betta is beautiful where did you get it?

 

colouring if I had to guess
just be careful to make sure you don't mistake it for a fungus if she ever gets one

btw your blue betta is beautiful where did you get it?

Thank you! I got them all from crappy Petco believe it or not - there is one near me that actually takes care of their bettas , unlike most of the other Petcos I have seen! It took a few visits , to a few diff Petcos to eventually find 6 females that were around the same age/size! But that one is my favorite - esmerelda - and she is such a pig she is almost double the size of some of the other girls! Lol here’s a better pic of her !

 

Lol
Where is your Petco?
Love the name!!!

 

Thanks! The somewhat decent one is in Fairfield, CT. The ones closer to me, I can’t even look at their bettas without feeling horrible for them!