Step 2: The Separation
Okay Click on the select by color tool.
Now click on the first color you wish to separate.
Copy this selection (ctrl + C)
click paste (or ctrl + V)
in your layers you should see a "floating layer" right click it, and click New Layer
Viola! Your color is separated! Just repeat the process for all of your colors, and you should be able to separate colors like a master in no time.