This list of variable should help with creating a consistent ui experience for the players, this is a list of element colours used by the arma 3 interface, an can be used to ensure that you custom dialogs match the players chosen style.
retrieve values using
missionNamespace getVariable ["<variable name>", <default value>];
for example:
missionNamespace getVariable ["gui_bcg_rgb_a", 0.2];
gui_bcg_rgb_a gui_bcg_rgb_b gui_bcg_rgb_g gui_bcg_rgb_preset gui_bcg_rgb_presetdefault gui_bcg_rgb_r
gui_grid_center_h gui_grid_center_w gui_grid_center_x gui_grid_center_y
gui_grid_h gui_grid_w gui_grid_x gui_grid_y
gui_titletext_rgb_a gui_titletext_rgb_b gui_titletext_rgb_g gui_titletext_rgb_preset gui_titletext_rgb_presetdefault gui_titletext_rgb_r
guipreset guipresetdefault
igui_bcg_rgb_a igui_bcg_rgb_b igui_bcg_rgb_g igui_bcg_rgb_preset igui_bcg_rgb_presetdefault igui_bcg_rgb_r
igui_error_rgb_a igui_error_rgb_b igui_error_rgb_g igui_error_rgb_preset igui_error_rgb_presetdefault igui_error_rgb_r
igui_grid_ace_displaytext_x igui_grid_ace_displaytext_y
igui_grid_avcamera_h igui_grid_avcamera_w igui_grid_avcamera_x igui_grid_avcamera_y
igui_grid_bar_x igui_grid_bar_y
igui_grid_chat_h igui_grid_chat_w igui_grid_chat_x igui_grid_chat_y
igui_grid_comm_x igui_grid_comm_y
igui_grid_gaugealt_x igui_grid_gaugealt_y
igui_grid_gaugecompass_x igui_grid_gaugecompass_y
igui_grid_gaugehorizon_x igui_grid_gaugehorizon_y
igui_grid_gaugespeed_x igui_grid_gaugespeed_y
igui_grid_gaugestability_x igui_grid_gaugestability_y
igui_grid_gps_h igui_grid_gps_w igui_grid_gps_x igui_grid_gps_y
igui_grid_hint_x igui_grid_hint_y igui_grid_menu_x igui_grid_menu_y
igui_grid_mission_x igui_grid_mission_y
igui_grid_notification_x igui_grid_notification_y
igui_grid_radar_x igui_grid_radar_y
igui_grid_slingloadassistant_h igui_grid_slingloadassistant_w igui_grid_slingloadassistant_x igui_grid_slingloadassistant_y
igui_grid_stance_x igui_grid_stance_y
igui_grid_vehicle_x igui_grid_vehicle_y
igui_grid_weapon_x igui_grid_weapon_y
igui_text_rgb_a igui_text_rgb_b igui_text_rgb_g igui_text_rgb_preset igui_text_rgb_presetdefault igui_text_rgb_r
igui_warning_rgb_a igui_warning_rgb_b igui_warning_rgb_g igui_warning_rgb_preset igui_warning_rgb_presetdefault igui_warning_rgb_r
iguipreset iguipresetdefault