I want to something like that (common cathode connected to WS2803 and RGB multiplexed by ATMega328p) But unfortunately my knowledge about 328p programming is very limited, so I take few pieces of code that I found on net and now it's kind of working but it's flicker (mayby not too much, but before …

Multiplexing WS2803

Grumpy_Mike October 22, 2012, 7:14am 4

I used MM74HC04M as buffers but that didn't work at all

Then you did not wire them right,