ColorMix Rainbow – Test & Demo Model

  ColorMix Rainbow Demo

A fun, simple 3D rainbow model designed to test and showcase the ColorMix feature in PrusaSlicer (2.9.6+) and EasyPrint.

ColorMix lets you create dozens of new colors from just a few loaded filaments by alternating thin layers. The slicer predicts the final mixed color and creates virtual extruders you can paint or assign just like regular ones. This rainbow is the perfect quick project to see the feature in action!

   What is ColorMix?

ColorMix is Prusa’s open-source color-mixing model. It interleaves layers of different filaments (similar to how inkjet printers mix CMYK dots) so the eye blends them into intermediate colors. Ideal for MMU, AMS, toolchangers, or any multi-material printer.

Official info:

- [Prusa ColorMix announcement](https://blog.prusa3d.com/our-new-open-source-colormix-model-in-prusaslicer-and-easyprint_136079/)

- [ColorMix Shading app](https://blog.prusa3d.com/introducing-the-colormix-shading-app-make-your-models-pop-with-realistic-lighting_136716/)

### Requirements

- PrusaSlicer 2.9.6 or newer (or EasyPrint)

- Multi-material capable printer (MMU3, XL toolchanger, AMS, etc.)

- Ideally 3–5 filaments (CMYKW works best for the widest color gamut, but any colors you have will work) 

      Recommended Print Settings

- Layer height: 0.10–0.15 mm (thinner layers = better optical mixing and smoother gradients)

- Nozzle: 0.4 mm

- Infill: 15–20% (or solid if you prefer a denser look)

- Supports: Usually none needed (depends on your exact orientation)

- Maximum width of a segmented region (Print Settings → Multiple Extruders → Advanced): set to 5 mm for faster prints and less waste

   How to Use with ColorMix

1. Open the 3MF (or import the STL) in PrusaSlicer 2.9.6+.

2. Load your physical filaments.

3. Click the ColorMix button (below the filament dropdowns) and create virtual extruders for the rainbow colors you want (e.g. red, orange, yellow, green, blue, indigo, violet) by mixing ratios such as 50:50, 75:25, 25:75, or 33:33:33.

4. Assign the virtual (or physical) extruders to the different bands/segments of the rainbow.

5. Slice and print!

The colors you see in the preview should closely match the printed result (especially with Prusament PLA).

   Files

- ColorMix_Rainbow.3mf – Ready for PrusaSlicer with ColorMix support (recommended)

- ColorMix_Rainbow.stl – Geometry only (you’ll need to set up ColorMix yourself)

### Tips

- Start with CMYKW (or close approximations: cyan/azure, magenta/pink, yellow, black, white) for the richest palette.

- Experiment with different mix ratios – small changes can produce surprisingly different shades.

- Print a small section first if you want to fine-tune the mixes.

- Check out the official [ColorMix Calibration Cones](https://www.printables.com/model/1726525-colormix-calibration-cones) for a systematic way to see all possible mixes from your loaded filaments.

### Inspiration / Purpose

I made this rainbow purely to experiment with and demonstrate ColorMix. It’s a quick, colorful way to explore the feature and show friends/family what multi-filament mixing can do.

Happy mixing and printing!

Feel free to share your makes – I’d love to see the color combinations you create.