Varius brown colors and transparent washes create all the shadows needed  for a realistic brick wall. All details painted separate and glued in plase after the weathering. Only a filter applied as a final step to unify all different colors in a balanced result

some details of the number 263 building

                        Painting the pavement wasn't much different except from the colors used

And the first test with all diorama's masonry painted 

Adding more shadows and dust