Actually detail is rather relative, so I gave it a lower possible score.
0 for none, 1 for slight (say a few rocks here and there), 2 for more detailed (more things have a level of detail to them than not)
Color actually has several things that I count. As everything has a color, this was hard to originally think of.
0 for bad color (say a bunch of random rainbow stuff colors or just solid black or whatever), 1 for bland (say just brown and gray, but still works for the build), 2 more colored/effort put into coloring (say different color planks for a floor supposed to be made out of wood), 3 for very well colored (basically like 2 except when the colors go very naturally together, usually this would require a custom colorset or whatever)
I still prefer the 0-to-π system.
Yes, but this just sets the limit on what I plan on giving them and justifies the scores. Your 0-to-n is usually a 0-to-10.