Additional "spread" interpolations
|interpolation, gradient, color, palette
When using the spread option in the palette editor only linear RGB interpolation is supported. Human intensity perception is not linear in nature so perhaps additional interpolation methods may be added as drop down options.
If you have normal vision you'll see that the "spread" from pure green to pure black feels weighted toward the green end. If you look here you'll see just how different interpolation can be. HCL seems blending might be something quite useful!