[Dillo-dev] ui colors again

Jorge wrote:

FWIW, an earthly theme sample with the new prefs:

ui_fg_color= 100404 ui_main_bg_color=c2a47b ui_text_bg_color=cdc9a5 ui_selection_color=763024 ui_tab_active_bg_color=af4b3f ui_tab_active_fg_color=white ui_tab_bg_color=d2b48c

It's nice. Should we regard bare hex as proper and legal? a_Color_parse() currently calls it an error but parses it anyway.