It would be neat to be in control of the canvas background color surrounding your artboards. If you work with colors close to the light / dark theme background the contrast might not be what you had preferred.
Hey @joakim 
Welcome to the forum!
To be clear, do you mean something that goes beyond the option in the screenshot below? Being able to define the exact color of the canvas, as opposed to just: Light/Dark/Follow system setting?
Thanks 🫶🏼
Exactly. Just use the a regular color picker for the canvas.