Feature Request: Paintable Canvas Side

[Pelzklops]

The wooden optic of the frame is really ruining many aesthetics since it often clashes with its surroundings. so a way to either have the sides of a painting be automatically colored the same way the border of the painting is, or even better, the ability to color that yourself would be very nice. This would also make sense, given that in real life, the fabric of a canvas is fixed to the backside of the frame, not the front, meaning that in actuality the sides of the canvas should be white anyways