Most of what you listed is an actual condition where the thing causing the problem is described by its actual color (snow is white, white heads are filled with pus which is also white...whereas black heads are filled with old and soiled pus..thus they are black). Black flags mean death and disease; white flags mean surrender because the actual color/emblem of the flag is considered beaten during battle...thus as a sign of surrender the colors and emblems are removed (so to speak) ...whereas during battle, the emblem and colors are brandished as a sign of warfare.

None of what you listed are the same as having a black heart, dark soul, dark attitude, dark disposition, etc.

I'm sure you can see the difference.