Festae Lost Her Color

I have had my Festae for a few years now. Raised her from 1/2". She has always displayed great colors. Recently, she has reduced her colors dramatically. Water conditions are decent, no competition in the tank (rehomed my green terror), she's been eating normally, not noticing any parasitic/fungal growths, but she does very occasionally rub herself against the sand. I have moved the tank recently, but she started to lose her colors about 2 or 3 days before the move. All other tank mates appear to be very healthy. Only potential competition is a newly added 4" salvini, but again, her colors have been reduced even before this addition.

The Transition:

She's only about 2-3 years old. Maybe 8". Yes decor has been changed, but she has a large cave for herself. Also, this color decrease went on a few days beforehand. Tank mates are: salvini, midasxparrot, and some misc fish. She's always been on top of the pecking order. No one challenges her.

Substrates been the same. I am a little concerned as I recently have heard her bumping around in her cave. Not sure if she's building a nest or if she's scratching. What sort of signs should I be looking for if something's amiss and are there any precautions I could take at this current point?