What are the dimensions of your 60? 48x12 or 48x18 base?
If it's large enough and you wanted some CA or SAs, pink convicts are 'colorful' CAs, or you could go with several pairs or singles of smaller and more passive species like chetumalensis (like convict but lots of reds as well), nanoluteus (yellow), honduran red points (very blue if you get a nice pair), etc. If you mix single CAs with pairs you are more likely to get crossbreeding, though.
SAs that are colorful would include angelfish, oblongum/red ceibal, gold/blue/electric blue/Bolivian rams, etc.
I personally would not mix most (any?) Africans with geos, but I like to keep fish from at least the same continentn in the tank, or with very similar water requirements. Probably skip the angelfish if the geos stay in the same tank unless it's a very calm geo as they get too big for the most part to play nice with the angels.
Most of this depends on the floor space in your tank and how much deco you have as far as plants, rocks, etc.