TL;DR: Colors get lost in OrcaSlicer when you load a 3MF as a project instead of dropping it on an empty plate. Set up your printer and filaments first, drag the Layerpaint file onto a clean plate, accept the Standard 3MF Color Parsing dialog, and your palette maps slot-for-slot. Here's the path that works and how to fix slots that land wrong.
Why do colors get lost when you open a 3MF in OrcaSlicer?
OrcaSlicer reads a 3MF two ways. File then Open Project imports it as a full project and can overwrite your printer and filament setup, reassigning colors if the import partially fails. Dragging the same file onto an empty plate loads it as a model: the colorgroup data comes through and you get the Standard 3MF Color Parsing prompt to map groups to slots. The plate-drop path is the one that keeps your colors intact.
OrcaSlicer treats a 3MF two ways depending on how you load it. Pick File → Open Project and the slicer reads the file as a full project: geometry, printer profile, filament list, color groups. If your current project has a different printer or filament setup, the import overwrites it. If the import partially fails, colors get reassigned to whatever slots already exist.
Drag the same 3MF onto an empty plate and OrcaSlicer treats it as a model file. The Materials Extension <m:colorgroup> still comes through, but you'll see the Standard 3MF Color Parsing prompt asking how to map color groups to filament slots.
A Layerpaint 3MF carries both: the standard color groups and a Bambu-style project_settings.config that names the filament type for each slot (PLA, PETG, ABS, or TPU). The trick is to land on the path that respects both.
The path that works
- Set up your printer profile and AMS slots in OrcaSlicer first. Pick the AMS unit, the number of slots, and the filament types you actually have loaded.
- Drag the Layerpaint 3MF onto the empty plate. Do not use File → Open Project.
- When the Standard 3MF Color Parsing dialog appears, leave the suggested mapping. OrcaSlicer reads each
<m:color>entry from the colorgroup and pairs it to the closest current filament slot by hex. - Click through and check the filament panel on the right. Slot 1 will be the unpainted-fallback grey Layerpaint emits as a sentinel. Slots 2 through N match your palette order.
- Reassign any slot that landed wrong by clicking the colored chip in the filament panel.
That sentinel grey at slot 1 is intentional. Layerpaint reserves it so unpainted faces don't get silently grouped with a painted color. The side effect is that your real palette starts at slot 2 in the slicer. If a model has no unpainted faces, you can delete the slot 1 filament without affecting the print.
If you drop a Layerpaint 3MF into a project that already has color-painted models loaded, OrcaSlicer appends the new color groups to the end of the existing filament list. Drag onto an empty plate to keep slot order matching what you saw in Layerpaint.
What about Bambu Studio?
Same routine, same dialog. Bambu Studio shows the Standard 3MF Color Parsing prompt in the same spot. The Bambu-specific project_settings.config Layerpaint embeds tells Bambu Studio what filament type each slot is, so you don't have to manually swap a slot from PETG to PLA after import.
If you want to bring the painted mesh into a Bambu Studio project you already opened, use File → Import → Import 3MF, not File → Open Project. Import-as-model preserves your current printer and AMS setup and just adds the painted object to your plate.
When the colors look right but the slots are wrong
OrcaSlicer assigns filament slots to color groups by hex distance, not by group order. Two things fall out of that:
- Two filaments with similar hex codes (a matte cream and a silk cream, say) can swap. Layerpaint orders the colorgroup the same way your palette is ordered, so check the slicer panel matches Layerpaint left-to-right.
- A color in your Layerpaint palette that isn't loaded in the slicer maps to whichever loaded color is closest. Either load the matching filament in OrcaSlicer before importing, or fix the mapping manually after.
The fix is one click per slot in the slicer's filament panel. There is no "rebuild from the file" button.
Common questions
Does this work with OrcaSlicer forks like Anycubic Slicer and Creality Print?
Yes. Anycubic Slicer Next and Creality Print are OrcaSlicer-based and read the <m:colorgroup> block the same way. Drag the file onto the plate, accept the parsing dialog, and verify slot assignments for the ACE Pro or CFS unit.
What if I paint more colors than my AMS supports?
OrcaSlicer caps imports at the slot count your printer profile allows. A 6-color paint job landing on a 4-slot AMS will collapse two pairs of colors into single slots. Reduce your Layerpaint palette to the slot count you can actually print before exporting, or split the model into two prints.
Does file size matter?
Not for color parsing. A Layerpaint 3MF stores per-triangle color groups, so a high-poly mesh produces a larger file. If OrcaSlicer takes more than a few seconds to open one, run the Simplify decimator in Layerpaint with Export Only mode. Your working file stays hi-res and only the export gets thinned.
Try it now
Paint an STL in the painter, export a Standard 3MF, drop it on an empty OrcaSlicer plate, and the colors come through clean. Free to try. A one-time payment of $19.97 unlocks 3MF export forever. No subscription.