Hmmm, OK, I might give that a try, but I'm still not sure if the refresh rate is going to be suitable. I think my previous displays were cycling at about 1ms per cycle and that produced a very smooth display. I guess your suggesting the shift register display could have a cylcle of about 8ms. I haven't seen RGB LED's blend at an 8ms cylcle but I do know I was using mosfets to drive the blending of colour and I found that not all mosfets produced acceptable results (some seemed to be too slow or something). Anyway, I'll do some investigation. Thanks for the suggestion.