Nothing high tech about this. Krylon's official website says that the paint works on fabric and suede. Kate and I picked out a color of spray paint that we liked. Tape over the label and the sole/heel of the boot. Spray twice. Peel off the tape.
I picked up a pair of beat down powder pink(now gray) uggs at a garage sale for a quarter. Those last few words were completely unnecessary and I truly don't remember how much I paid, but that was a line my grandma would always say. We'd unwrap a present from her and she'd say, "Oh, so you like it, well I got it at a garage sale for a quarter." It always made the value of her love drop a bit in my child eyes. So, if you've come here for child-rearing advice, there's a gem for you.
I admit that when I showed these to my sister and told her what I'd done, "I spray painted them, dude." Her response was something like, are you an idiot? As soon as they get wet, you know how snow melts, right? Well they're gonna be wet and they're gonna drip reddish pink all over your carpet and house and couch. And my response was something like, no. But with the commitment of someone who basically knew they were the mentally inferior sibling.
Update-- No leaking of color at all. The boots are a bit crusty in the beginning, not soft to the touch like they were pre-spraying, but that's not a big deal to me. I sprayed the boots with a rain proofing spray special for leather goods.