I've begun texturing the sculpture scans using Substance Painter. This is something I didn't think I'd do at first and it's definitely adding a lot of extra work. Originally the plan was for all the sculptures to use the same plain white material. However, after testing how the textured statues look I've changed my mind.
In most cases it's much easier to identify details on the textured statues than the non-textured ones and the realistic textures help make the sculptures pop out from the simplicity of the rest of the garden. In the above image, areas of the sculptures marble texture reflect the passing light differently.
At the moment there's a black and white filter over the entire game. However, I might consider having statues show their colour when selected which would involve swapping all materials to grayscale rather than using a filter.