Coloured mortar is much more than the medium for bonding bricks and blocks. It can also be an architectural tool, accentuating or subduing brick colours and textures. It can make the most of clever brick patterns or bring light relief to what might otherwise be monotonous. While one colour can be chosen to harmonise with the brick, another offers a contrast.
There are a variety of other factors that affect the visual appeal of the finished face, such as brick texture, pointing type, local exposure and the prevailing lighting conditions.
"The Brick Development Association
recognises the benefits of using such a mortar particularly when,
as is often the case with coloured mortar, they enhance the overall
appearance of the brickwork."
Driver MA Dip Arch RIBA Brick Development Association.