In Rhino 7 (7.3.21026.13002, 2021-01-26), I’m unable to define a Face Color for a closed extrusion (i.e. Box).
What I do is select the target face with SHIFT + CMD and in the Properties panel under Face Color, click on the small button that makes the color selection window pop up. Now, if I select a color and hit Apply nothing happens, and the small button remains in a pressed state.
Is this a bug or is it simply not possible to edit the colors of individual faces of a polysurface?