In general there are a few rules when it comes to pot colour selection that are based around aesthetics in order that your bonsai trees are displayed to their advantage.
Gambody STL files of Hobbiton Bonsai Pot for 3D Printer
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A Beginner's Guide to Bonsai - Dengarden
A Helpful Guide to Choosing the Right Pot for Your Bonsai
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A comprehensive guide to bonsai trees, by Bonsai Tree Help
How to care of your maple bonsai and not die trying
Bonsai Pot
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How to Choose a Bonsai Pot For Your Bonsai Tree
Shimpaku Juniper — Bonsai Society of Victoria
Bonsai pots - why they are integral to bonsai aesthetic and health