Although there are many techniques such as using photoshop with multiple BSE images from different Quadrants, we recommend the use of MountainsMap SEM by Digital Surf.  This software makes the process fast and painless, as well as consistent.  An article about this technique by Digital Surf was published in the May 2018 edition of Microscopy Today
Download HERE or use this direct link to the Microscopy Today article vault: LINK
Mignot, C. (2018). Color (and 3D) for Scanning Electron Microscopy. Microscopy Today, 26(3), 12-17. doi:10.1017/S1551929518000482