neolamprologus leilupi - yellow, from lake tanganyika
aulonocara baenschi has vibrant yellow flash (malawi).
various aulonocara (peacock) hybrids are red - you may see tham as 'sunburst peacocks) (malawi).
good specimens of Protomelas taeniolatu are a wonderful vibrant red on blue base (malawi).
some variants of aulonocara jacobfreibergi have red base.
some tropheus moorii (sp. red) have stunning red trim on black, some are predominantly red (tanganyika). e.g
http://www.cichlidforum.com/profiles/species.php?id=1910.
note, tropheus, while wonderful fish, are a bit of a specialty and need to be kept ideally in large colonies - they should be the 'main focus' of the tank if kept.
in your tank I would do tangayikanss - a tropheus colony (say 15 or so) - they are fantastic. I would also have some leilupi, for the yellow.
I would also consider 3 - 4 frontosa, for a very, very nice contrast, and some synodontis catfish, for variety. Imagine this tank with pale rocks, pale substrate, black background and some plants. Spectacular !