[blenderbim] appending a wall type from a library doesn't transfer material colour

[brunopostle]

This IFC library contains a single wall type with a layerset containing a single material that has a yellow colour.

If I load the file and create a wall from this type, the new wall is yellow.

If instead I create a new project and append the wall type from the library, everything required seems to get appended (layerset, psets etc..), but the IFCMATERIALDEFINITIONREPRESENTATION for the material doesn't - a wall created from this appended type isn't yellow :(