There have been plenty of times where I (r/g colourblind) have been able to see paint mis-matches on red coloured cars where people with normal vision haven't seen an issue, and I've been able to tell at a distance which panel has been refinished. I think the input/output curve of my red perception is non-linear compared to normal colour vision, and while on a lot of that scale it is a deficiency, in some situations, I have improved sensitivity.

Having said that, I'd trade in a heartbeat, so I could see bloody charging LEDs properly.