GtkColorButton: Reduce internal use of deprecated API
GtkColorButton: Reduce internal use of deprecated API

Drop the blanket GDK_DISABLE_DEPRECATION_WARNINGS and avoid
deprecated API as much as possible.

Sidnioulz/SandboxGtk,davidgumberg/gtk,ahodesuka/gtk,chergert/gtk,ahodesuka/gtk,alexlarsson/gtk,chergert/gtk,jadahl/gtk,jadahl/gtk,Sidnioulz/SandboxGtk,jigpu/gtk,Sidnioulz/SandboxGtk,Sidnioulz/SandboxGtk,davidgumberg/gtk,grubersjoe/adwaita,ahodesuka/gtk,chergert/gtk,jigpu/gtk,Adamovskiy/gtk,Lyude/gtk-,ahodesuka/gtk,alexlarsson/gtk,jessevdk/gtk,chergert/gtk,Lyude/gtk-,chergert/gtk,jadahl/gtk,jadahl/gtk,grubersjoe/adwaita,jadahl/gtk,Adamovskiy/gtk,jessevdk/gtk,davidgumberg/gtk,grubersjoe/adwaita,Adamovskiy/gtk,Sidnioulz/SandboxGtk,ahodesuka/gtk,jessevdk/gtk,Lyude/gtk-,alexlarsson/gtk,jadahl/gtk,jessevdk/gtk,Lyude/gtk-,alexlarsson/gtk,Sidnioulz/SandboxGtk,Adamovskiy/gtk,Lyude/gtk-,grubersjoe/adwaita,alexlarsson/gtk,jessevdk/gtk,ahodesuka/gtk,jessevdk/gtk,Adamovskiy/gtk,davidgumberg/gtk,chergert/gtk,grubersjoe/adwaita,Adamovskiy/gtk,ahodesuka/gtk,grubersjoe/adwaita,jadahl/gtk,jigpu/gtk,davidgumberg/gtk,davidgumberg/gtk,jadahl/gtk,jigpu/gtk,Lyude/gtk-,chergert/gtk,alexlarsson/gtk,Lyude/gtk-,alexlarsson/gtk,Adamovskiy/gtk,jigpu/gtk,Adamovskiy/gtk,jigpu/gtk,grubersjoe/adwaita,Lyude/gtk-,jigpu/gtk,alexlarsson/gtk,jigpu/gtk,ahodesuka/gtk,jessevdk/gtk,davidgumberg/gtk,grubersjoe/adwaita,davidgumberg/gtk,chergert/gtk