RGB: it has, red, green and blue LEDs, produces red, green and blue light and the combinations of these 3 colors. White light is produced by the 3 LEDs together, so it will look more or less blue. RGBW: it has all functionality of RGB, plus it has extra white LEDs which can give out cool white color. White light is produced by the pure white LEDs only, so it will not look blue, but cool white