What color is this one supposed to be?
The one I have comes white with maybe a little cream and the yellow stamen area.
Some of the local garden centers are selling "Primevera" as a double yellow?

I've never heard of it before, but that doesn't mean anything. I googled it and this is what I found on "Help me Find" http://www.helpmefind.com/peon...

I think the one you have is the correct one.

In 1907 it was as near to yellow as they had. The petals are supposed to open a creamy yellow then fade quickly to white. Also at that time flowers of this type were classed as doubles. Now would probably be classed as Japanese or Semidouble.