[Feat]: Default color for IfcType

[MicolaL]

What is your idea?

Hello,

with web-ifc if IfcGeometry color is not defined color defaults to white (dunno if there are some exceptions). Would be usefull if we could define default color for each IfcType. For example most IFC Viewers use blue-grey color for IfcSlab, Revit uses dark grey etc. Currently only alternative seems to traverse getMaterialsProperties() to findout if there is IfcColourRBG assigned. Please let me know if there are some other options that I am missing.

[TrabacchinLuigi]

i would consider also alpha. glass transparent, but also ifcbuildingelementproxy or ifcroom should be barely visible