The flashing alongside of my chimney had come away from the brickwork - slightly - and I could see daylight. Someone working elsewhere in my house at the time sprayed filler in the gap. This has closed the gap (which was not very big) but the filler is white and has dried into a polystyrene type texture. Is there anything I can apply to this white filler to tone it down as it looks suspicious to any would-be buyer.