Font Color / Background  
Changing these colours influence all highlighters by setting them all with the same color of font or background. So, be careful and test it out.  
Selected Back / Selected Font  
Background and font colours of selected text.  
Current Line  
Background colour of current line.  
Right Edge  
Colour of right edge marker. If you want to hide it, set the same color as background.  
Background colour for left gutter.  
Spell Check  
Color for underline mark when Spell Checker is enabled.  
LOG parser  
If you fill Log parser string in compiler settings then after clicking in LOG window, this will be background colour for corresponding line in the editor.  
Color for matching bracket highlighting.