If you feed them a primarily predatory diet from a young age they will get aggressive- and ugly. In the shop I worked with a few people that were obsessed with feeding fish to fish- guppies, goldfish ect. Idiots. The chocolates there were crazy aggressive. They also looked terrible.
Not in my tank, they all usually hang out together and the pairs can't decide which side of the tank to spawn this time around. In the 220, I have 6 and I see the same in there, the Chocolates in the 220 share it with 4 Cutteri, Eel and plecos.
I am growing one of these out with a few severums. Nice fish for sure, mine hasn't colored up much yet but he changes color with mood and is kind of grouchy towards the severums sometimes. He never follows through with any threats though just kind of flares gills and pushes his buddies around.
I notice that mine is just neutral with everyone only one that gives him a hard time is my female marbled convict but he just stand his ground and swims away to another spot of the tank. Pretty passive I gotta say
I found them to be pretty passive despite their large size as adults. Of course they were in the tank with some pearsi, so they would have to eat their wheaties if the thought they were going to do anything
This beast just came into my LFS and although alittle beat up he is awesome. He is right around 10 inches of badassery, I think this is the biggest chocolate I've seen. Although I'm no expert on them. Anyways apologies for the bad pics just had to snap a couple.
I got three of them a few years ago and they were super peaceful for the most part. There was a little conspecific aggression but it was a ling tank so the odd man out had a place to run to. Great fish.
edited to add: my experience with the colour of these fish was that they changed all the time. literally all the time. the tank mine were in was pretty bright but they usually had lots of reds and greens, i dont know if it was the brightness that did it. i'm sure being paired helped