Labels and folder

Why is it if "Colorize icon with labels’ is NOT checked and the label is the length of the name, all folders change color to yellow and is different than the folder used for the OS? I might use the labels in the name but why do I want a new and yellow folder?

Groups having a yellow icon are used for tagging, blue groups are excluded from tagging (see Info panel). But you can also exclude all groups from tagging via the Database Properties panel.