Pretty much what it says on the tin: how do you disable nano's strange feature of colouring the leading whitespace on a blank line. If you're writing a program with different amounts of tabs on each line then sometimes you'll leave a line blank to space things up to make it easier to read, but there will be unused tab characters on the line left blank as they're placed automatically. nano seems to think it appropriate to colour the line's tabs if it's blank, but actually it's distracting and out-of-place.