When one is giving a presentation with Impress, one can draw on the presentation by right-clicking and choosing ‘Mouse pointer as Pen,’ and can change the color by choosing ‘Change pen Color…’
However, both of these require opening up a context menu on top of the presentation, and changing the color requires opening a dialog as well. Is there a way to enable the pen tool and change its color using keyboard shortcuts, to prevent showing context menus and dialogs to the audience?