Yellow marks on white bikini

[onesteptwosteps]

Help! Any ideas how to revive a white bikini that has gone yellow around the armpits especially? I've tried vanish powder and vanish bar but it's made no difference. TIA!

Sunlight. Lay it out in the sun for a few hours should help.

Elbow grease spray may do it, then wash and put in the sun to dry.
The astonish stain remover is supposed to be good too but I haven't tried that one.

Thanks - I'll give those a try 👍🏼

could it be suncream related? Dye it a darker colour?