You want colors to be meaningful, diverse, and stable. You also want the color map to scale gracefully (both in semantics as well as in code). Hash some meani

You want colors to be meaningful, diverse, and stable. You also want the color map to scale gracefully (both in semantics as well as in code). Hash some meaningful value (e.g. class) to hue in HSV, and then you have your color. For distance, bucket by meter and lerp the hash-HSVs of the nearest bucket edges. Hash to color is the most flexible colormap.