Andy wrote:

FWIW I would also remember that dead smooth and perfect bricks look boring,
and the really interesting handmade types tend to be somewhat irregular in
profile, but quite frankly you'll have your work cut out achieving a
half-decent result at all: I have some experience in trying to match colours
and textures in pebbledash etc, and it really does cut your work out to get
a good match.

Real bricks, and boring fake bricks that I have drawn:
http://i3.tinypic.com/27y33g1.jpg (81K)

It would certainly look better with random changes of colour.
May I suggest growing a creeper over much of the wall if it's fake.