Use the polygonal lasso tool to select a wall, then right click selection and layer via copy. This will separate each wall, allows more flexibility, multiple colours, turn layers on and off etc.
If the walls already have a reasonable amount of colour you can probably go Image > Adjust > Hue/Saturation and adjust the colour using hue.
If the walls are closer to white then you can add colour using Image > Adjust > Photo Filter
Both ways should maintain natural shadows and highlights of the building. |