There is this special thing called "Shoe Dye", you can buy it in shoe stores or probably find some on the net.
I would not use acrylic - the best thing would be to actually dye the fabric. They are canvas so dying the entire shoe with normal clothing dye may work but I am worried about permanence. There is the other problem that any plastic parts will be dyed also - though the results may be interesting.
EDIT : Read additional - I would mix PVA glue with acrylic paint in that case, it mixes very easily - if you want it to shine even more mix Citadel dye with it. Any gloss thin paint with PVA glue will add more shine. You can mix glitter with the glue too - I'm not sure how that will go, the glitter will sit on the surface but PVA is waterproof and dries as something which is similar to PVC.
Let it sink into the canvas, that way it will dry as a total piece - it's one form, a chunk of plastic (depending on how thick you use the glue).
I've done the same thing on some steel capped boots many years ago - right on the metal, after I cut the leather away. It was red and looked like dripping blood. A very nice effect I suppose. I have heard that many artists mix PVA glue with paint to add shine, texture (sometimes as it's glue - you can even put pasta in it :/ ) and effect.
I said to someone online a while ago that they should do the same (blood PVA glue, red dye / paint) with some fairy wings they were making. They wanted blood but just used paint instead. My method shines and looks quite realistic but effective- It will also be waterproof and bendable for you shoes. Any acrylic should mix with the glue. It's more durable for a shoe and won't crack or run.
Someone else said just use acrylic - that seems ok