Your choice of clour for listed cottages is limited, as it is, in this village, for any building in a conservation area.For the cottage you can have a very dark green. Nobody in living memory has ever seen one in that colour, but the jobsworths in the Council can't argue with it.
But that's a small matter. You can get abiding conditions enforceable against other owners. A friend lived in Rose Walk, Purley. She was obliged to have only roses of a certain colour in her front garden, and no other plant. On the other hand, you do get daft exceptions. Another friend, a lawyer, naturally, researched her conditions.She found that "no business or trade is to be conducted from [the house]". That was a standard condition,still found. But she read on.It continued "SAVE the testing and manufacture of aircraft engines". The house was in a road called Hangar Lane. That was a clue! The prospect of someone installing an engine for a 737, just to test, had not been within the ken of the draftsman in the 1930s, but it must have been tempting to try.