Since update 1.16.3-fabric 3, there is a new incompatibility with Optifine/optifabric that makes life bars floating above target look "milky". Whatever color these bars are supposed to be, they are rendered in a white-ish, ultra saturated version of it.

This defect is not present w/o Optifine.

This is currently (1.18.1) resolved

I've also noticed it makes entries full bright

Oh strange. I will install optifine and see if I can reproduce it.