Its more to do with placement, and wall type and colour.
Most of our RGB controllers have a dimming function on the static colours so it is possible to dial down the brightness.
Flexistrip LED tape is probably a better solution as this can be cut to the nearest 5cm of the desired length. ie if the length is 152cm you would cut to 150cm. The flexistrips have a 3m double sided tape on the back making mounting very easy.
Have you thought about control for the LEDs.