Using the TCS230 color sensor and a servo in one single program doesn't work because they both use Timerone.h. So I used two Arduino Uno's with a simple hard-wired master-slave communication line (Tx - Rx) between them. The measured values of the color sensor are corrupted though, as soon as I connect the two units. Even connecting digital out from the measuring unit to analog in of the servo control unit (to indicate a simple ' go to next servo position') seems to corrupt the measuring data from the color sensor, rendering it useless. It almost looks like the pwm signal to the servo is creating too much interference... Anyone?
The example code here uses Timer2 so it might work with the Servo library:
Absoloutly no need to use two arduinos.
The interference is coming from the servo, you need supply decoupling. You should not be using PWM on a servo anyway you should be using the servo libary.