Colored blocks next to names?

Is there a chart that explains what the colored blocks next to everyone’s names mean? I know it relates to how many woots purchased, but what’s the color/number progression? And is it all 3 woot sites combined or is your color different depending on which woot site you’re posting on?

This stupid question has been bugging me for a while now.

Your purchases from all three sites are combined. I don’t know if there’s a chart but I think there’s only like 4-5 colors… black being the highest. If you hover over the box, it will tell you the range for that color.