Rated 4 out of 5 stars

Very nice and useful ...but I don't have the "More Colors" entry available. Wonder why.

This review is for a previous version of the add-on (0.9). 

More Colors

> I don't have the "More Colors" entry available. Wonder why
"More Colors" is available from v1.0 which I uploaded today and is awaiting Mozilla review. Please try it should you feel comfortable with its status: "not yet reviewed".
https://addons.mozilla.org/en-US/thunderbird/addon/color-folders/versions/?page=1#version-1.0