I see a lot of videos where people’s “white” or “sparkle” is bright and clean. Are you using WS2811 (RGB), or is there an equivalent (RGBW) 12 mm available? I have not found one yet.
Yes there are IC chips designed for RGBW, such as WS2814. Compared to RGB, RGBW adds in a dedicated white LED.
I personally have not considered this for my display since I find RGB is already bright enough (actually too bright IMO without limiting brightness to well under 100%).
There may be someone else who has experimented with WS2814 or another kind of RGBW IC who could comment further.