public void modify_base (StateType state, Color? color)
Warning: modify_base is deprecated since 3.0. Use override_background_color.
Sets the base color for a widget in a particular state.
Use override_background_color instead
Note that “no window” widgets (which have the gtk_no_window flag set) draw on their parent container’s window and thus may not draw any background themselves. This is the case for e.g. Label.
To modify the background of such widgets, you have to set the base color on their parent; if you want to set the background of a rectangular area around a label, try placing the label in a EventBox widget and setting the base color on that.
the state for which to set the base color
the color to assign (does not need to be allocated), or null to undo the effect of previous calls to of modify_base.