I am working with a Revit model, I am trying to colour the model before creating a tileset. When I check the model in the FME Data Inspector I can see the colours in 2D but they are missing in 3D. And that's why I am not getting coloured tileset.

Try using the AppearanceSetter instead. For 3D/Surfaces it tends to work better if you have an Appearance rather than a feature color. Feature colors tend to be more for vector features like lines and polygons

@virtualcitymatt​  I tried AppearanceSetter but unfortunately, it is also applying colours only in 2D, not in 3D. In the data inspector visual preview, I can see colours only in 2D. The 3D one is still colourless. I have only surface geometries.

Hmm, by default the AppearenceSetter applies geometry to those only in the 'Root Node' position. Maybe the structure of the geometries is a bit complex.

You can try changing the 'Geometry XQuery' parameter so that is matches what I have below. This should match all geometries going through the transformer

@virtualcitymatt​ This query made some difference. I got it coloured this time in 3D as well. The only issue is it's generating it with a single colour, can I get 3-4 random colours?

I see you are grouping by "UinqueID" - you could use an AppearenceStyler to define a custom style for each UniqueId. Or alternatively you can create groups with more features and use this. If you are using the AppearenceStyler you wont need to put anything into the AppearnceSetter - just pass the Appearence to the Appearence port.

Actually, I am using AppearanceStyler. I removed colours from AppearnceSetter. Getting the same result. It contains only one colour.

@virtualcitymatt​ It worked. Thank you so much. I don't know why I didn't think of generating random colours using a AttributeCreator😂 . I learned something new. Thank you.

Yeah - unfortunately for some reason you can't attribute values in the AppearenceSetter only the AttributeStyler which is a bit of a pain but this method works at least