Thank you for the quick response! I believe I have found an idea that could possibly solve this problem without the need for complex color analysis, through the use of multiple voxel layers. I separated the house in three different Z-Ortho files: one for the base, one for the roofing, and another one for the hay bale, like so:
I loaded each of them individually in Pixzels, and then combined them in Photopea to demonstrate the shape I originally intended to make:
However, it would be amazing to have all shapes loaded at the same time in the program, so that they can cast shadows on one another, and to easily export several angles. Thanks again for your time and effort!