one thing to keep in gray theme :)
http://imageshack.us/a/img202/3107/f2lx5jvrvckvg2dp0jyocij.png
Color combinations could be endless LoL
http://imageshack.us/a/img850/3107/f2lx5jvrvckvg2dp0jyocij.png
this is the best solution, which makes the site unique in its kind.
The 'visual appearance is strictly personal and is helpful in reading the code,
could confuse too many controls, so it's only fair to give everyone the opportunity to choose the background color and the text code.
If this is not enough to clarify the text, use the zoom + in your browser LoL
is a good idea Mr. Hawkee
something out of place ?
my opinion is dark background, I think it's more suited to a dark theme of the site where they highlight the contrasting colors.
Maybe it's the color of the text that would appear highlighted with yellow color is opaque $rgb (255,155,55), dark red $rgb (205,0,0) and white
They approach good of soft colors like light pastel, a gray opaque green for example ...
In any case, how do you plan to do, the work is finished like this idea :)