It's crazy how many coral are one of those two colours or both combined Why? What's YOUR Most colourful? what about white? That is alive still not dead. Lol.
Scolys have red and yellow and many chalices are red and yellow and Acans are reds, blues, yellows and I have a monti thats pink and they come in blue with yellow edges.
Ricordia can be orange, blue and yellow, Blastos are red, yellow, blue
Red diablo
Most pay the bucks and get zoa's they are all different colours
rule of thumb for coral is the brighter and more crazy the colour pattern the more you are forking out to get it... zoos are easy for quick colour and grow fairly fast and easy. those crazy acros can get into the hundreds quick so is more how much your willing to spend. lots of montis are great for colour and have alot of variations in growth structure. In my opinion chalice and brains get the most crazy colour patterns but they get up in price as well. I mostly have pink, blue, red, orange but lots of things have a tone of greenoor purple somewhere.
As for white corals that are alive most are deep water acros that have very specific requirements to keep properly and a few that require super intense lighting but are rare. They are normally white with coloured tips.