Muddy colour Primulas - for Siris

Is this a cross with the native primrose and your red and yellows?

Siris, I believe that it is a cross between these two:

http://www.growsonyou.com/photo/slideshow/316653-primula-vulgaris/member/klahanie

"Muddys" are not in the picture but they are next to it. They are all native. I did not plant them. And they seed and multiply freely. Many colours too.
I have other hybrids too the Belarinas and Candelabras that I planted and hybrids in the pot (presents from our neighbour)

I started with many coloured Primulas, but gradually they are dumbing down to 'Muddys. I always remove some otherwise I would end up with just those.

I am creating a little border with mostly primulas for spring show. I cannot grow many plants because of our wildlife. No one likes to eat primulas, except slugs. It will be interesting to see the colour changes. I heard of many other plants (peonies for example) are doing the same thing, but I have not noticed on mine. I wonder about your irises now.

Iris do not change colour. What often happens is that a strong growing variety expands into a weeker neighbouring clump, sneakily. Bearded Iris can be produced by crossing different colours, but it is a lengthy process, and the results are very variable.