How to get Converse trainers white again

[Electrocute1980]

I bought some lovely converse earlier this year, white with lilac tongues. They needed cleaned so I washed them in the machine but they've come out an off white instead of the lovely bright white they were! Any ideas for getting them bright white again?

Toothpaste(whitening) I've not tried that one so cant recommend! If you use kiwi trainer whitener or trainerwhite not sure if 2nd is still around x