Is it possible to change the colour of the screen behind the canvas from the default white? The white colour, because of the glare of my monitor, makes it hard to see the edges of paintings with darker, subtler colours. It washes out the subtlety. This is because the eye adjusts to that bright white border. I would much rather it be black, really, since a black border works equally well for dark and bright paintings (it doesn't interfere with them, anyway).
There's no problem if the painting takes up the whole screen, of course, but if it's an irregular size then that bright white colour can be a problem.
If this is not yet possible, I think this might be a useful and not-too-difficult feature to add.