If you check the drab, washed out coloration of the JD in the link below, you will notice that many cichlids tend to wash out their colors when substrate is white, reflective or un-natural. Those un-natural substrates also seem to make waste sitting on the bottom more obvious.
Geophagus natural habitat is natural color sand, so will appear best with that color.
If a natural display isn't your thing, of course, then disregard,
Male or female Jack Dempsey