When using a file from Maker the tower shows three colors. The problem is the part has only two colors. How to remove the third color? I tried putting the file into a cad system and then resaving each of the components as separate stl files. Yet when importing them the third color reappears. Very annoying. I have seen this on multi-part files using multi-colors.
Who colored the model? There could be a missed color dot someplace. Are you using supports or brim. Are they one of the two wanted colors? How about the infill?