Help with sourcing RGB LED Tape

Dear all,

I am working on an interactive sculpture at the moment. It uses RGB LEDs and ultrasonic sensors, to allow people to colour mix as they move around the piece.

Because of the colour mixing side of the interactivity, the bog standard RGB LEDs from ebay or Amazon that I have been using previously aren't quite good enough to get really evenly mixed colours, as the component green, red and blue LEDs are unevenly matched.

I have done a dirty hack with a friend to correct the LEDs in my programming but I was wondering if anyone had any knowledge in RGB LEDS and would know who would be good to buy from? In terms of getting a good quality led tape that is not too expensive. Aside from me just ordering loads from the internet to see what they are like - I thought I would ask here first.

Spec required:

5 metres (possibly more but lets start with this)
300 LEDS
Black PCB or White PCB
does not need to be individually addressable but if you think that the LED quality may be better because of this, then could get this type.

Also is there a way to diffuse the tape without using the plastic covering? The sculpture requires the LEDs be able to bend around come tight angles so the plastic sheeting is no good, any ideas?

Any suggestions, companies that people have used before that they think are good.

I look forward to hearing from you,