RGB Wash LED bar

Does anyone have an idea on how to control the rgb LED wash bar, depicted in the following image, with an arduino? Note the the LEDs are not RGB, they are respectivelly Red, Green and Blue LEDS. They are powered with 220V. If I just power the bar there’s a routine running but I would like to control the color of the bar.

That’s a DMX fixture, its controlled through a DMX controller.