[alias_neo]

It's an interesting idea, and how it would work with colours other than "bleached" would be the interesting part.

Presumably it wouldn't work on black without fading the garment, but given how we've seen things fade in shop windows, I wonder if there's some novel applications for removing other types of intentional "stains" like ink, or paint, and particularly if they're under/behind a surface like a clear-coat or glass or something else that prevents physical access.

[blensor]

I wonder if you could remove blue ink with yellow light. Specifically residue from ballpoint pens on furniture.

[alias_neo]

That would be an interesting one, I have a strangely related story that not too long ago my toddler drew _all over_ a yellow suede sofa with a blue ballpoint pen, was a nightmare to get it out without making the pristine sofa look like a drowned rat.