In arcscene, all you have to do is right click the layer--> properties --> rendering tab --> and select 'Disable material textures'. I can't find the equivalent in Pro
strange, the only reference with those key words is in What's new in ArcGIS Pro 1.1—ArcGIS Pro | ArcGIS for Desktop
and it is associated with Layer 3D To Feature Class—Help | ArcGIS for Desktop
but you could start in the latest 'whats new' and work your way back in case I missed something
What's new in ArcGIS Pro 1.3—ArcGIS Pro | ArcGIS for Desktop
I found a workaround by exporting the layer to a shapefile since shapefiles do not support layer texturing.
Retrieving data ...