black ruby barbs

I was watching my 55 gallon today at breakfast, and just marveled at how well it turned out. Going in, I fully expected my Black Ruby Barbs to be my least favorite fish in the tank. But they really add such a huge pop of color to the tank. When I got them they were pretty bland, but they have...

A recent discussion brought to mind feeding my fish veggies (which I try to do every week). Usually I feed frozen veg, but my boss had some fresh zucchini from his garden, so everybody got a chunk. Here are some of the denizens of my 55 eating a slice.

It looks like some of my male Black Ruby Barbs are starting to develop some nice colors. Is there anything I need to do in order for them to stay colorful, other than the usual WCs and food variety? In a 55 gallon community tank at the moment.