How to get school blouses white again?

[SugarPlumpFairy3]

I've been checking dd's school uniform to see if I need to buy any more over the summer. Her uniform was on the big side last year so I'm expecting it all to fit again next year .

The only problem seems to be that her cotton blouses are a little grey looking. It'd be a shame to buy new so how do I brighten them up? I've tried soaking in Oxy powder but they still don't look great.

Any ideas please?

I soak them for half an hour in really dilute bleach or milton, wash with plenty of powder designed for whites and hang in the sun to dry.

Whites have to only ever be washed with whites. Not nearly white, not quite pale, not partly white. Otherwise they pick up dyes and go grey.

You can try as hot a wash as the label says, with a powder (not liquid) and add half a cup of washing soda crystals, in case it is not transferred colours.

Liquids do not contain bleaching agents. Cool washes do not clean as well as hot.

I see this a lot you can tell who doesn't separated their white. Put them out on a really sunny day.