You could do like a blackcap basslett or a purple or helfrichi firefish. The helfrichi is $$$ though as I have one in my IM Nuvo 20. Or you could do a cool pair of clowns like snowflakes or picassos
20 Gallon SPS reef
29 Gallon FW "fat catfish" tank
20 Gallon Long Dart Frogs "Zig" and "Zag"