well in that case i think you should go for a community tank.
some possible colorful fish would be...
boesmans rainbowfish; fancy tail guppies; mollies; swordtails; cherry barbs; cories; dwarf gouramis; blue gouramis; pearl gouramis; neon tetras; rummy nose tetras; danios; harlequin rasboras; clown rasboras; black widows; black neon tetras; emperor tetras; hatchet fish; penguin fish; dwarf cichlids; keyhole cichlids; lemon ciclhlids; checkerboard cichlids; angelfish; killifish; pearl catfish; loaches; rainbow fish; platies; pictus catfish; white clouds;
you can google pics of these to see what they look like if you dont already know
and the cichlids that i listed are some of the friendly ones :D