yeah, a pair works as long as the female is much smaller than the male at time of introduction. Same species/colour will generally get along fine, if you lucky they will become a mated pair but they don't do this all the time, wont kill each other but will get along.
Different colors will kill each other in the end.
Here is a video of them trying to do their mating dance, i had changed the flow and they couldnt find a quiet spot to do it, so they gave up in the end, its lovely to watch this every night though.
Have to excuse the quality it was an iphone video