Is there a way to give slight color variations to a scene (a straing of purple here, some yellow blur there) without adjusting every single texture? And for that to work in VR stereo images too (and ideally in semi-consistent way as one moves around, and perhaps also without having to use computing-heavy colored lights)? Many thanks!
I’m not sure if it will achieve the effect you’re after, but it sounds like a job for the “Post Processing Stack”, available on the asset store for free. Attach the included “Post Processing Behaviour” script to your camera(s) and create a Post-Processing Profile for it to use. If you’re wanting to tweak colours in your scene, look at the “Color Grading” and “User LUT” settings; that’ll probably give you the results you’re looking for!
It looks like a colored, global Directional light, which uses a cookie with a very blurred soft randomization texture (and rotated with 90-0-0), does a nice job for this.