We're about to do lime wash on one of our heritage buildings. We decided to use ochre as pigment because it comes from earth. My boss says with any pigment that comes from earth, we don't need to worry about discoloration in lime mortar, which is high in pH value. But some of our guys are using laterite powder for brick repairs and I wonder if it is a good choice. Would it discolor in lime mortar? How would it react? Please, someone answer me!
Maybe I need to mention more info in my question. I'm from myanmar and we've got a lot of sunshine and a lot of rain too during moonsoon season. We're not doing new buildings, just repairing a historic building built around 1900. This building is basically abandoned for decades, and it's quite big. A lot of bricks need to be replaced, but in some areas we intend to use lime mortar with brick dust to imitate a brick rather than raking out and replacing with a new one. But we're not achieving the same color as the original brick but when we add laterite powder to lime mortar, color is satisfactory. Our only concern is that we don't want the repaired areas faded away after three or four years.