Single lines displayed from KML appear white

[pmolsen]

When I create a model with single lines (eg. the support cables on a suspension bridge) and set Styles to display lines by material, and colour the lines a certain colour, they appear correctly in Google Earth when I view the model from SU and from the 3D buildings layer.

If I save the model as a Collada file and create a KML file that refers to it, when displayed in Google Earth the lines all appear white regardless of what colour they are.

Is that a bug in GE or a limitation or am I doing something wrong?