I need 35% Black. I can't edit any of the colors on the palette, "edit colors" is grayed out. Can one create or edit a fill in Photo-Paint?
Try using a different approach...select a fill by right-clicking on a color swatch on the palette, and then use EDIT>Fill (CTRL+Backspace) to edit the fill. You can also double-click the Fill icon on the Tool menu to get to Edit Fill.