For the Schematic, its pretty easy. Its just an RGB-LED 5mm diameter directly connected to the pins of the Arduinos. Resistor for every color Pin is 180 Ohms and they have common Cathode.
Well, you just proved my point. If the led is connected directly to the pins of the Arduino, where are the resistors connected? And resistors do not have cathodes, common or otherwise. English is crap compared to a schematic, for describing a circuit.