Man pages matching name desktop_color_depth in section 3alleg4:

desktop_color_depth.3alleg4.en	debian 10 / allegro4-doc
desktop_color_depth.3alleg4.en	debian 11 / allegro4-doc
desktop_color_depth.3alleg4.en	debian 12 / allegro4-doc
desktop_color_depth.3alleg4.en	debian 13 / allegro4-doc