Illness/Sickness: Axolotl gills looking funny??

[DaisyFlower]

Hi!
I got my axolotls on the 25th, and everything's looking good. I just had a query about my gold 'lotls gills? The feathers look fine, and she's kinda shy, but she ate some fish off of me the other day and she seems happy and healthy.
The tips of her gills are looking a little brown, and I haven't noticed it before. It could just be her colouration, but I wanted to share some photos to see what people think. I'm kinda new to this, so I'm just paranoid about everything...
The water levels are perfect (I had them tested at my aquarium), and she's on sand.

Here's some photos of Mango's gills.

 

[notanaxoltl]

she looks happy and healthy to me, if she’s eating and the water parameters are fine I wouldn’t worry.