Getting the color back in my Rainbows

[HybridHerp]

so, my rainbow sussed to be a bright bright yellow but now they are often much much darker, one of them being black most of the time
fish are healthy, but I want recommendations for getting the color back
I think they might have colored down after I added a geophagus brasiliensis to the tank, which was bigger and is probably the second most dominant fish in the tank

I feed a wide variety of food but am always open to suggestions. Only other thing I can think of mentioning are that the tank is a hi-tech planted tank with hi-lights and the temp is about 76 (I used to have it higher but found that the plants did not approve of this)

 

[dent20]

I would guess it's the addition of the Geo. How big is the tank and do you have a male/female mix of rainbows in the tank?

 

[rrcoolj]

I would guess it's the addition of the Geo. How big is the tank and do you have a male/female mix of rainbows in the tank?

+1 they are probably showing submissive coloration to avoid being harassed by the geos. Geo brasiliensis tend to be pretty nasty especially compared to a non aggressive rainbow. What size tank are they in and how big are the fish?

 

[ryansmith83]

+1 they are probably showing submissive coloration to avoid being harassed by the geos. Geo brasiliensis tend to be pretty nasty especially compared to a non aggressive rainbow. What size tank are they in and how big are the fish?

That's my guess. Also, mine didn't really show the bright coloration unless I had A) spawning, or B) a dominant male trying to stare down a submissive male.

 

[HybridHerp]

its a 75 gallon planted tank
funny thing though is that the rainbows were never the dominant fish, the geo is usually busy dealing with the blood parrot (or rather, the parrot with the geo) nothing serious though
other funny thing, its like 2:30am and I checked on my fish cause I was up anyways, and their colors were a lot brighter at night
also, I am not fully sure the genders of the rainbows, I originally bought 3 in hopes that I could get a pair out of them, but it looks like I have a group of 3 males (though tbh I haven't gotten a good look at their vents, nor can I catch them and pull them out in order to look)
the rainbows were incredibly colorful when they were with just the angels and the blood parrot
even though the geo isn't the boss of the tank, I guess the presence of 2 larger fish is more intimidating than the parrot alone was.

 

[clc013]

Yeah, rainbows are pretty moody fish. Money's on the addition of the new geo. In time, they might get comfortable enough to display some color again.