What do you think about adding the ability to change text color and background color for line numbers within Settings : Editor : Margins and caret? In Code::Blocks 17.12 (current version), the left margin inherits the background and (?) foreground colors from the OS's color scheme. We may want to add a checkbox for optionally disabling Code::Block's current behavior. The label might be 'Use custom colors', or alternatively: 'Use system default colors'.