In the indoor optical communication, it is essential to provide the multiple-access function, the dimming control function, and the positioning function. A variable N-parallel code shift keying (VN-CSK) system using Modified Prime Sequence (MPS) codes has been proposed as a method that satisfies these functions. Even though the lighting devices are composed of RGB-LEDs, this method treats each lighting device as a single point light source. Thus, this method enhances transmission efficiency. In this paper, extension of VN-CSK system to the parallel RGB-LED transmission was proposed. This system uses four kinds of RGB-LED with different color power to represent white light. In addition, the symbol error rate performance of the room model when the transmitter uses these four types was evaluated. Using area ratio achieving specific SER as an index, which LED is most appropriate for VN-CSK was decided.