Ranked in these QuestionsQuestion Ranking
Pro Comes in 5 different variants
Comes in 5 different variations: Tomorrow, Tomorrow Night, Tomorrow Eighties, Tomorrow Blue and Tomorrow Night Bright.
Pro Eases visual processing
Different colors within the same color scheme to quickly distinguish the layout (px, %, ..) and other declaration blocks from the colors (background-color; color); that eases the visual processing, thus increases reading speed, while reading CSS.
Pro Light & dark themes
Dark theme does a good job of contrasting kvps.
Pro There are versions for a lot of applications or it's easy to make your own
There are ready-made packages for Vim, IntelliJ, Emacs, iTerm, etc.
If your app isn't supported the website explains clearly what colors are used, so it should be easy to wrap up your own.
Although not mentioned in the list of supported editors, on GitHub you can find a folder Notepad++ with xml files.
Sadly it does not seem to work with newer Notepad++ versions ...