We tried to stick with descriptions for colours that Heuer themselves used. Even where those seem wrong (e.g. describing watches with dials that are clearly silver with the generic "white").

They tend not to specify colours of subs in the brochures. We do have the option of "charcoal grey" as that was the colour of the 1153 N dials initially. Looking at the barrel-cased models, the registers of a 110.515 are significantly darker than those of either 110.573 - still not quite black but close enough to earn the description. That would let us call the 573 F and B registers charcoal grey and hopefully not give cause for too much confusion/individual interpretation.