polygonColor function
Implementation
bool polygonColor(Pointer<SdlRenderer> renderer, Pointer<Int16> vx,
Pointer<Int16> vy, int n, int color) {
var co = Uint32List.fromList([color]).buffer.asUint8List();
return polygonRgba(renderer, vx, vy, n, co[0], co[1], co[2], co[3]);
}