Any plant that does not bloom true to what it's parent plant is, is a sport.

As for the predominant color... I'm not sure about leaf-chimeras, but I know flower chimeras I have'd had go both ways.

I side with Taxonomist. If you have let's say blue-white chimera and you put leaves down you can get solid blues and solid whites.Probably most of them will go after the main color. Yukako is a bit different - if propagated by leaf or by sucker - it strangely gives solids as well as sometimes chimeras even from a leaf - chimeras I saw besides true Yukako could be purple on purple - barely seen darker stripe - and white with green stripes.

Irina