Shading Tool not drawing

Am I doing something wrong? Even after selecting the colors, the brush does not draw… Whether in colored or grayscale sprites.

Not sure if this is the issue but afaik, the shading tool only works on one of the colors selected in the shading range.
I.e., you can’t draw new shapes, only shade the existing shapes. You need to switch back to simple ink and you should be able to draw again.