Lyvu is a lightly contrasted GTK2 theme with hints of color here and there. GTK3 version coming soon.
It utilizes the Murrine and pixmap GTK engines, so be sure to install them beforehand.
I made it relatively easy to change the default blue color to any one you may like, just open up the "gtkrc" and change the selected background color at the top of the file.
If you find any problems with the theme in any way, please comment below to report them so that I can fix them up!
(I am using the i3 window manager, the Any Color You Like icon theme, Liberation Sans, and Profont in the screenshot.)