Hello! Mainly, in this video, you will find the solution to this problem: When you Duplicate an Object in Blender and change its material or colour, by default, Blender modifies both meshes. Watch to find out how to fix it! Thank you!
Don't have Blender? Download it here:
https://www.blender.org/thanks/
0:00 Intro
2:19 The Issue
2:45 Fixing The Issue
3:58 Conclusion
6:23 Outro