The menu bar icon in Yosemite with enabled Dark Mode looks ugly.
Yes, it could be nicer.
Do either of these work? - nearly black:
defaults write com.binaryage.TotalSpaces2 menuBarIconColor 111111
Blue:
defaults write com.binaryage.TotalSpaces2 menuBarIconColor 0850d0
(Paste the commands into a terminal window then restart TotalSpaces2. The default value is 444444)