My brush is set to black but it appears grey onscreen

[JoeStrike]

This just started happening about a half hour ago. I was drawing in black, brush and layer set to 100%. Everything was fine...then for no reason I can figure out...my lines began to appear grey onscreen. They reverted to black for 1 second - & now they're grey again.

Maybe I changed a setting w/out realizing it - any suggestions?

[JoeStrike]

The color shifts from grey to black & back to grey again without warning...driving me cuh-razy!

[JoeStrike]

All setting are at 100%, including flow