Rainbowduino v3.0 external resistors

Hello I would like to assemble custom led matrix, and I would like to ask where or how should I setup external resistors, according used LEDs. In Rainbowduino v2.0 were 3 variable resistors so I could setup exact value, but I cannot find this on v3.0.
Thanks for answer

Sorry to tell you, version 3.0 Rainbowduino is different with 2.0 so in feature is completely changed´╝înow is only supply about 20mA. 2.0 can use almost 350mA.

So additional variable resistors is not allow.