In chroma.js, there are named color palletes or 'scales' such as Viridis, Spectral, RdYlBu (Red, Yellow, Blue), Reds, Greys, etc. I know some of these are based on Color Brewer. However, I do not see a complete look up table in the docs for these names with their colors. How can I know that such acronym would work such as "RdYlBu"?