Matplotlib is expected to support bivariate colormaps soon (see [PR #29221](https://github.com/matplotlib/matplotlib/pull/29221)). However, these colormaps can't be added to `cmap` since it doesn't support bivariate colormaps. From what I understand, adding this functionality would require major work. That said, I'm opening this issue just to start a discussion. ### Other implementations - [`biscale` R library](https://cran.r-project.org/web/packages/biscale/vignettes/bivariate_palettes.html) ### Relevant reading - [Designing 2D colormaps](https://trygvrad.github.io/designing-2d-colormaps/) - [Multivariate colormaps for n dimensions](https://trygvrad.github.io/multivariate-colormaps-for-n-dimensions/)