Paints can be mixed to whatever color you want to have. If you're unsure of what colors to mix with what, ask a friend that is an artist painter. Next is that brick really isn't one color. Aside from the different bricks in different areas being different actual colors, weathering also changes the color of a brick. Finally, the individual bricks in a building are usually a range of colors near the basic color and this is something that you may not have noticed. After you do the basic color, you'll have to go through and temper each brick with some wash to bring out it's own color on the wall. After that, you can add in the mortar lines and weathering of the whole wall.
-- Yeppie, Bush is such an idiot that He usually outwits everybody else. How dumb!