How to set color on GtkTreeView column header with CSS

1. create

GtkTreeView

with the

GtkTreeViewColumn

and

GtkCellRendererText

as normal;
2. get the

GtkButton

inside

GtkTreeViewColumn

;
3. add custom name for the

GtkButton

with method

GtkButton::set_name($name)

;
4. load css data with

GtkCssProvider::load_from_data

;
5. create

GtkStyleContext

and add provider to the screen, to css be accessible for all widgets;