Note

This page is generated from a Jupyter notebook. Download the .ipynb from the sources, or open the paired jupytext .py under docs/tutorials/.

Backgrounds and RYB paint mixing#

White / transparent canvases and subtractive RYB mixing. Concepts and figures: color compositing. CMYK is API-only in the combine-mode dropdown pending GUI polishing — available as combine_mode='cmyk'.

RYB paint mix vs additive RGB

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import multicolorfits as mcf

Backgrounds (preferred over inverse=True)#

Classic combine_multicolor(..., inverse=True) plus hex_complement() was the v2 route to a light canvas. Prefer an explicit background:

s.compose.combine_background = 'white'
s.compose.combine_background = 'transparent'
s.compose.combine_background = '#F5F0E6'   # custom
s.compose.facecolor = 'none'              # transparent figure canvas when saving

In the browser GUI the Compositing tab exposes the same choices (and a side-by-side montage of white / RYB / transparent): gui walkthrough.

RYB (paint-like subtractive)#

s.compose.combine_mode = 'ryb'
# blend is ignored for RYB/CMYK — chroma mixes subtractively
rgb = s.render_combined()

Or with the low-level helpers:

rgb = mcf.combine_colorized_layers(colorized_list, mode='ryb', gamma=2.2)

Yellow + blue → green on the paint wheel (not cyan-ish white as in additive RGB). That is intentional. For additive Lab mixing that keeps hues distinct under bright overlaps, use combine_mode='lab' + combine_blend='screen'.

When to use what#

Goal

Setting

General science color composite

Lab / screen

Classic channel sum

RGB (combine_multicolor)

Paint / ink aesthetic

RYB

Print-ink invert feel

CMYK (API)

Slides with irregular outline

transparent background + cutout export

 
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print('Backgrounds + RYB — see docs/guide/color_compositing.md')