The idea is that the code is not a Christmas Tree. For readability sake whole theme must be bright (bright, warm background) and text must be black - there is a reason for books to be made that way for centuries. Another goal is distraction free... As a human you are genetically predisposed to react on bright colors, especially red color. So in toned there is no red or yellow, unless there is something wrong that need your special attention.

Code is classified into four groups, which corresponds with colors:

• green - control structures
• blue - data (values, eg. string)
• black - regular code
• gray - less important code (comments, semicolons)

There are exceptions from this classification, like regexp, which are brown/orange, embedded shell code - pink, and few others...

I work primarily in Ruby, so this language is best covered, other languages that are in some way covered are HTML, CSS, JavaScript (JS is hard to deal with), C ... Although I try to create generic rules, this theme requires more adjustments and should be treated as "work in progress". Also it's tested only on Sublime version 3.