Which type of background should be used for this panel. Possible values are "none" - the default GTK+ widget background will be used, "color" - the color key will be used as background color or "image" - the image specified by the image key will be used as background.
Kedu ụdị okpuru nke a ga-eji maka paneelụ a. Valiu mmenwu bụ "gtk" - difọọltụ GTK ahụ+ a ga-eji wijeeti nke okpuru, "color" - a ga-eji kii ụcha ahụ dịka okpuru ụcha mọọbụ "image" - egosipụtara inyogo site na kii inyogo a ga-eji ya dịka okpuru.