Sending RGB values from Max/MSP to arduino

Hello,

I am trying to send RGB values from MAX/Msp to Arduino with a serial connection.
The connection is establish and i can send data, so far so good (but only for one variable)
But how can i identify different data and assign them to a couple of variable in the arduino sketch,

For example: the serial sends: R255, G100, B160
R245, G90, B150
etc.
Then i want to assign them to the variables red, green and blue in the Arduino code.
I've searched the web a lot but i couldn't find a solution.

Hopefully you guys can help me out!

Thnx