Hi Hugh!
I suppose, that the gm2d svg renderer doesn't support 'fill-rule' attribute yet, like in the svg renderer in haxelib. The source of these two are similar.
I added some colour definition in SVGData.hx, to support 'white', 'black', etc. colour naming.
I try to add fill-rule support, and if it works, then i will post to public my version.