Exporting from Tinkercad to Sketchfab in Colour
Step 1: Export Your File
Export your model as an OBJ. It will save as a .zip file.
Step 2: Import to Sketchfab
Import your model to Sketchfab. Make sure to import both the OBJ file and the .mtl file. The MTL file will give the model it's colour. If you don't import this file, your model will have no colour.
Step 3: Add effects and Manipulate Colour
In the 3D editor, you can chance the look, background and do much more to your model.