Changing Drawing Colour
When you press the “Palette” icon from the Drawing Toolbar, you will be able to select a colour to draw with.
Undo and Redo
You can do so by pressing the Undo and Redo buttons in the Drawing Toolbar.
If you hold the Undo button, you will be asked if you want to clear the entire drawing.
Colours will be maintained when during undo and redo operations.