Black paint didnāt really exist until late 19th century so any iron work or lampposts you see painted black, in a period Christmas movie for example, would in Charles Dickensā time have been light blue, green or grey.
Yeah they couldnāt make it in any great quantity.
Also missing from the painterās palette was a strong black. Permanent black paint, distilled from tar and pitch, wasnāt popularly available until the late nineteenth century. So all the glossy black front doors, railings, gates, lampposts, gutters, downpipes and other fittings that are such an elemental feature of Londonās streets today are actually quite recent. If we were to be thrust back in time to Dickensās London, one of the most startling differences to greet us would be the absence of black painted surfaces. In the time of Dickens, almost all ironwork was green, light blue or dull grey.