Swap a symbol with fade from a button?

Hi I am trying to swap a symbol using a button, but also have the old symbol fade out and the new symbol fade in.

For instance say I have this blue circle with two arrow buttons to move forward and backward through a series of different colored circles. Like a red green and a blue one.

When you click on the right button it should change to red, if you click it again it should change to green. If you were to click the left one now, it should take you back to the red.

SO I basically want it to cycle you through the 3 different symbols. Unloading one, and loading the next. As an extra nicety, I would like the one that is leaving fade out, as the new one coming in to fade in.

I am not sure how to begin to do this, so if anyone can help, i would really appreciate it.