Colouring Help

[chrisjj]

Where in the Help can I find explanation of the colouring that appeares between the line number and line?

Thanks.

[joendsu]

You may be talking about the "Gutter" background color. This can be changed in the options (Tools-->Options). In the File Views, Display. "Edited" and "Saved" are also part of the gutter, they have specific colors for indicating that. Default of Yellow for "Edited" (Changed, but not saved yet) and Light Green for "Saved" (Changed and saved).