Wires etc.. sometimes are white. Block update next to it fixes it.
https://ibb.co/cccdoQ
https://ibb.co/fy0yoQ

And for some reason when I made this thing with rotating light: https://ibb.co/iUVnhk , the white part thing happened sometimes to gates in my hotbar.

Reloading chunks (f3+a) makes the ones close to you disappear. It can be this bad: https://ibb.co/cHGrsk

Graphics settings: https://ibb.co/fCLUdQ

This is fixed in 1.12.

Joining this thread, seen same behaviour, which way white wool texture correlates uncovered redstone at all?