Liquitex Fabric Medium turns normal acrylic paint into fabric paint.....
I'm not entirely sure about the longevity with washing etc, but it might be worth a go. I've experimented with it a few times. I suppose you could just use acrylic paints, but the medium seems to keep it from drying out too quickly and also the finished product is less stiff.
I also have fabric paints in crayon format (for my nieces, the messy little darlings). You just iron to set them permanently.
https://www.bakerross.co.uk/fabric-crayons