What changed? And is it indoors or outdoors?

FataMorgana

mint rust looks like link below

Here is a link that might be useful: mint rust

they grow indoors... and i don't know what changed, they get plenty of water and sun as usual one day they started to have this purple spots on 2-3 leaves now its all over the place and the new ones also grow purple and not healthy...

about the mint rust, i think it could be the case, but from what i read in the link it pretty much says that i should get rid of the plant and the contaminated soil... :(

any tips how to prevent this in the future?

For the future, can you set your pots outside? Mint prefers outdoor conditions.

FataMorgana

I don't have a garden yet. i keep them on the window they get plenty of sunlight there during the day... whats else could made this happen ?

I've had what appears to this mint rust. At the time I didn't know what it was and I would just eat those leaves as I saw them, leaving only perfect leaves alone. It went away for me. I do this with all my plants.