This is a color version of the original Ramp2D macro from Shake's cookbook.

Setting the alpha channel individually unfortunately comes with premultiplication in NGLRender, which is bad in most cases, so I decided to avoid individual setting. The alpha channel is just a standard monochrome version of the colors you set, without premultiplication, therefore good under most circumstances.

(No icon needed for this macro! It will be automatically linked when you start Shake!)