To add to this colour study, Revit does not display colour nor transparency.
Revit is technically not IFC4 certified, but it is nonetheless the most commonly used tool in the industry … that said, if your file was IFC2X3, the colours would still not work in Revit.
@ian if you would like a deep-dive into why exactly colours may or may not work, this thread goes through in quite a bit of detail. In addition, this post describes the prerequisites for colours in Revit.
I have seen lots of ifc from the proprietary vendors which use different colors for the material assigned to a shape and for the shape itself. Thus no wonder different software show up different colors.
@bernd: this is not illegal although I agree it should not be the norm (I have seen it more as the norm). There is an implementer agreement in place that when both are provided, the shape style overrides the material style.
The output in Revit:
And yes! @bernd you are absolutely right - this is IfcPlusPlus / IfcQuery - another uncertified open-source, free software implementation that displays both colour and transparency correctly.
