01
Look at a representative area
Compare slate samples beside several bricks, mortar joints, and nearby trim. A close match to one brick may create a different overall effect when the wall is seen as a whole. Review the combination outdoors under the lighting in which the building is normally viewed.
02
Choose the relationship deliberately
The roof can complement a dominant tone or provide a quieter contrast. There is no universal pairing that works for every brick and architectural style. Ask the designer to show the combination at building scale before committing to a large order. Record the slate selection independently of the wall description so a future repair does not depend on an informal phrase such as the brownish one.