Any idea how to get these stains out? Pic attached

[Bream]

This is the canopy part of a gazebo thing we bought last summer. Is there anything that would take these stains out? I tried washing it in the washing machine already and it did nothing.

Anyone? Can I bleach it perhaps?

Is it a rust stain ?

Lie flat in full sunlight should help.
Depends what the stain is though.

Elbow grease or vanish gold

Glycerin works for rust

I’m not sure what the yellowish brown stain is, but the blackish ones are mildew. We left it out over the winter which was obviously really stupid. Will try vanish gold! No to bleach then?

Soak in Milton overnight

A solution of bicarbonate of soda works on mildew.

Ok thank you!