Rated 4 out of 5 stars
Although 'More Colours' appears in the Context menu, only the colors in the base menu can actually be applied. TBird 6.0.2, Windoze 7 Pro 64-bit.
In reply to the developer, no other extensions are installed.
Mmmm. Your environment is exactly the same as mine -- Win7 pro 64bit + TB6.0.2. It is working as you see in the screen shot. I trust you have clicked one of colors in color picker palette. The issue could be conflict with other extention. What does happen if you only have Color Folders enabled in your extentions?