Transistor Biasing of high side switching network for PWM control
simulate this circuit &ndash; Schematic created using CircuitLab

A circuit similar to this I take it. Where each of the CLK signals go to an arduino to generate the PWM? The drive resistors need to be (5v-(Vf of LED)-(Von of transistor))/10mA (V=IR or V/I=R) and the LED usually need around 10mA for good full drive.
Note: Each input will turn on the LED when it is low and not high. A low turns on the transistor.