I made that same observation, I wonder why that is. Also looking at Matador some cvs have dark anthers before they release pollen. I rarely see this trait in cvs that are yellow or pink, so it may have to do with red pigment. Any thoughts charlie?
I also notice the same cv's will have a change in color on the stigmas, this could be the same thing you are seeing too , Chris. I seen some yellow stigmas on one cv and then I saw some more pictures of the same cv but the stigmas where a orangier color.
With my research I have only found these dark stigmas in only Red flowers or fushia pink flowers like passion play.