rgb led and rotary switch problem

Hello again...
While i was making my test according with mu old schema, i found out that I couldn t switch to different color....every time my blade was always white.
This happens because the current flows in the r-g-b even when is not supposed to.,.. So to solve my issue i'm using diodes as the following schema shows Attachment 13997

Now... Do there is a way to avoid using so many componenets anf without using micro-programming/arduino?

@fenixfire how can i have my yellow on hit while the lines are disconnected by the switch? Any clues?