Same background for all four of your themes, with different color solutions. I like it!!! Definitely "MSP Crew Carbon" is the theme that I like best. It's dark but not too dark on the "New Tab" home page. If you want to modify I would leave the "Icon Attention" orange, the new tab text orange, the link folders I would leave white but the highlighting of those folders I would make orange as well as the border of the popup window.

dark and distinguishable, like it.

Awesome without exagerate