unusual dahlia

I have two colours growing on one stem is this usual? genuine photo.

 

Not something I've seen before on dahlias - though I have seen it other plants where there's been a lot of crossing of varieties.

 

I think they call them "sports", when a plant puts out flowers of a different colour.
Its how some of the new cultivars are created, by propagating the new coloured parts.

 

Thanks, I'm not really a flower grower and I thought the photo looked a bit suspicious shall I post or not ..glad I did now. have a nice weekend.