The main thing is to not pick a saturated color that will clash with anything in the picture/video. Otherwise, a very light color (white or close to it) or a v

The main thing is to not pick a saturated color that will clash with anything in the picture/video. Otherwise, a very light color (white or close to it) or a very dark color (black or close to it) will probably make the picture/video more visible. FWIW, older users seem to prefer light backgrounds, and younger users seem to prefer dark backgrounds.