I downloaded the fixture profile for the 25-channel Gamma Borealis RC, but it doesn’t seem to have a control for the secondary “background” LEDs. What am I missing?
It is possible that the fixture profile is incorrect. I would send an email to Vista, because it appears that feature is not implemented correctly in the fixture control. Or alternatively in the Vista Community Discord Server you can send in a fixture profile request, and we be able to make a custom fix for you here: Vista by Chroma-Q Community
Usually those items do not fit the generic fixture model so they are in the Custom Features tab.