How a printer changes colour mid-print
A multicolour FDM printer does not mix colours — it swaps filaments. An AMS or MMU holds several spools and, when the slicer says a different colour is needed, it retracts the current filament, loads the next one, purges the old colour out of the nozzle, and carries on. Every swap costs time and a little wasted filament, which is why multicolour prints take longer and why you will see a purge tower or a pile of purged blobs beside the print. The result, though, is a figure that comes off the plate already coloured: the suit red, the straps black, the eyes white, with no painting.
Why the model has to be built for it
You cannot take an ordinary single-body STL and paint it in the slicer with clean results. A model prepared for multicolour is split into separate bodies — one per colour — that fit together exactly. That is what makes the difference between crisp colour boundaries and a smeared mess. When you open a multicolour-ready file, you will see those bodies, and you assign each to a filament slot. If a model is not built this way, the slicer's paint tools can approximate it, but the edges are never as clean as a properly separated model.
Setting it up: slots, purge and orientation
Import the file, keep the bodies grouped so they stay aligned, and map each to a slot — red suit, black straps, white eyes, silver blades. Check the purge volumes: switching from a dark to a light colour needs more purge than the reverse, and under-purging leaves a dirty transition. Enable the purge tower if your slicer wants it. Orient the figure upright on its base and print at a fine layer height, since the colour boundaries look sharpest when the layers are thin. Expect the print to take several hours longer than the same figure in one colour, and budget a little extra filament for purging.
Single-colour printers, and the finished alternative
If you do not own a multicolour machine, the same file prints as an ordinary single-colour figure, and Deadpool in particular takes paint well — red body, black straps masked with tape, a dab of white for the eyes. It is a satisfying evening's work. And if you want the figure without any of the tuning, purging or painting, the studio prints the same model in full colour and ships it finished.
