The handling of missing 'from' is partly wrong. It often takes the standard values and not current or previous value af an attribute. Comments in the code talk about handling missing 'form' during animation, but this doesn't happen. This causes problems on Path, Color or Points-animations. Try to add tests later.
Color got fixed. Working on Path fix right now.
I have a complete fix for all primitives, to correctly use either the previous value or the empty value (which has special meanings for eg. transforms: zero matrix needs to be used, not identity, etc.).
Bug can be closed, its all fixed.