Green food colouring was spilt on to a ceramic tile. The colouring found its way to the edge of the tile, between the cupboard and edge of the tile, where it was absorbed through the porous part of the tile and is now visible under the hard glaze on the surface of the tile. I have poured bleach around the edge of the tile which has moved the stain from the edge to the centre of the tile. Any ideas on how to remove the stain?
