Lots of choices...
Red - red monty cap, rose BTA, blastos, lobos, monty setosa (while incredibly bright, they tend to be smaller than other choices)
Purple - purple tipped frogspawn or hammer (I loved these whan I had them), lots of acros
Blue - many acros are blue or have blue tips, there are several blue chalice, some montiporas have a blue base or blue polyps
Of course mushrooms, zoas & palys will cover all of the above colors also...