After print failure cant extrude PLA
If the hotend is okay, consider yourself lucky and consider the nozzle a loss. Aside from specialty items like ruby tip ones, nozzles are a consumable anyway. Even if you can clean it out well enough to get it working again, it's unlikely to extrude as well as a new clean nozzle. Acetone is probably not going to help; PLA does not dissolve in acetone, and while the pigments/additives might be affected by it enough to weaken and deform PLA in a way that could get it to detach, what's clogging your nozzle is likely burnt/carbonized PLA that's unlikely to be removable by anything that won't also destroy the brass.
If you don't already have replacements on hand, get yourself a pack of 10-20 for $10 or so and be ready to replace when needed. You can also go for a mixed-size pack if you want to try printing fine details with a smaller (0.1-0.3 mm) nozzle or super-fast but rough with a large (0.8-1.0 mm) nozzle.