blue rams mating?

The male will chase the female around and both will color up nicely. You may see them wriggling at each other, but sometimes rams will do that to indicate aggression. I have seen my female start "flashing" behavior before spawning...but not every time before a spawn. You will notice both of them cleaning an area they have selected as the 'nest' by "puffing" water at the spot....or creating a 'dish' in the substrate. If you see them doing that it's a sure sign..especially if the female's belly is bigger than usual which could indicate she has a belly full of eggs.

Just watch them, once they are both ready to spawn you'll see them start biting at areas in the tank to "clean" them for the eggs. After that unless you have another larger tank, leave them be with the eggs and let nature take its course.