For that, I'd honestly mix some fabric dye in the color you want. Thicken it up a little with normal acrylic paint (but just a little) and use a stencil to get it on. It will be like using watercolors, but won't look painted on because it's not. This
is where I used acrylic paint. On the brighter orange (the flowers and the pattern on the sleeves, not the medallions). I think it photographed well, and didn't look painted on. I would pour some normal acrylic paint (except for the gold, which is fabric paint) onto a plate, dip my paintbrush into some water and use it to mix, then paint with that and rinse my brush ever three or so dips. Try it with some test fabric to find the consistency you like.