I was thinking it'd be fun if a border colour was automatically chosen to suit the average brightness/value of the photo inside.

The current white border around prints is very jarring on certain photos, and can even make some darker photos feel washed out and difficult to view properly as the eye is drawn more towards the border than the photo itself.

Instead of just dimming the white border to play nicer with more photos, I think it'd be cool if the border simply changed brightness to better compliment the photo. Perhaps the border or the text on the print could even be tinted with a prominent hue in the photo.

I've attached a mockup of how I imagine this looking.