Drop a Circle shape.
The Content Panel shows the fill color has blue, but the Paint editor shows it as BLACK ==> Bug.

Now, from the Paint editor, set the value to different colors, let say RED, GREEN and finally BLUE.
Undo. The fill color come back to BLACK (instead of GREEN).
Undo again: nothing happen
Redo: GREEN
Redo: BLUE
Seems there is an issue with the undo, redo is ok.