Full colour 3D models on Wikimedia projects would be a really great addition, there are 10,000 of openly licensed full colour 3D models available online.
**File format options**
There are several open file formats to chose from:
# glTF 2.0, work has already been done on supporting this file format, see T187844
# AMF supports material, texture, constellation and metadata, allowing you to show full colour models. https://en.wikipedia.org/wiki/Additive_manufacturing_file_format
# If supporting AMF isn't possible for a some reason 3MF may be an alternative open file format that could fulfil the same need https://en.wikipedia.org/wiki/3D_Manufacturing_Format
# .obj can only display shape information, adding .MTL support would allow .obj to display colour but would be really fiddly and not user friendly at all and would require supporting 2 new file formats