My own job was an extension and loft conversion where we raised the ridge by about a metre. That left the top part of the gables a different colour to the original bricks. The only bricks I could find that were close in texture and shape were virtually white where our bricks are a creamy yellowey orange sort of colour. With Dybrick you make a base colour and you buy small pots of fixer which you mix with water. We used base colour plus 3 mixer pots which made up about a gallon of liquid. It goes a long way. That gallon did about 30 square metres and we still have about a third of it left. I started by painting it on brick by brick and ended up spraying it on with a garden sprayer. The walls and gables have blended in perfectly, The only place it's visible is the top of the chimney which is a bit off because the original part of the chimney was slightly darkened by smoke from the log fire. But even then people can only see it when I point it out to them.