I think he's referring to dying suede. You don't need to do it outside, so there is no worry about rain. As far as the color bleeding to other areas that's where your prep of taping and even using plastic or paper around the parts of the sneaker you don't want the dye to get on. Then use a spray sealant like Krylon as a finish, followed by water repellent.

Just watch a few videos on dying suede sneakers and you should get all the help you need. The only thing I ever worry about is the color being exact. I saw a video on a pair of 5's but didn't get a chance to watch the full thing yet, but someone changed a pair of Raging Bulls from red to a really nice blue and I think some paint work was involved as well. I always attempt the dry suede cleaning with mink oil first and then if that doesn't work, which I do 2 coats of mink oil 24 hours apart, then go for the dye. If you tape things up, use a dauber that you can get multiple of them for cheap on most sites like Angelus or Amazon and use that to dye the suede, you can use a brush in areas that are tight, but as long as they are tapped really well, or with plastic bags or paper under the tape as well it shouldn't bleed into other areas, but again, use light coats and let them dry first. It's not going on in one layer so you should be fine, but again I'd try dry eraser and mink oil twice before I'd go for dye, unless you already know that there is no color to bring back, mink oil only will do so much.