Please chime in. These two colonies have been this way for the past 7 months. Not sure why.
One colony just above mid tank the other below mid tank. Radion Pro G3 are 10" above water line and tank height is 30". Other acro colonies around it are doing just fine and are colored up.
It's in stress.
Check your PAR on that spot.
Good point also to check for AEFW, this can be a sign of this.
Turn it over and look with a yellow flashlight, you can see bite marks if you have them and clusters of eggs.