I painted the brickwork mortar grey, then dabbed on brick red/brown with a kitchen roll, trying hard not to get it in the mortar courses. Further variations of red, dark brown, and orange were used to pick out individual bricks, or dabbed over areas.
The roofs were given several coats until I got the colour about right, the last being a well thinned black to emphasis the detail. I have made up some doors for the workshop, and all the "woodwork" was painted a dark red/maroon similar to that at Tatton. It's a rather nice colour too, I used it previously on Southon Yard! It was then lightly weathered with thinned acrylics.
As a reminder, this is one of the buildings at Tatton Park Farm, which shows the styling and colouring I am aiming for:
Actually that's not a great comparison because of the tungsten lighting I photographed the models under, verses the overcast daylight of the prototype! Never mind, I think it is close enough. Just need to add glazing and they will be ready to plant on the layout, although I also need one more building ...