Hi SarahJane,
Seed size can vary between different cultivars of the same type of flower. So smallness does not necessarily mean bad seed. If the seeds came right out of a dried flowerhead as you described, that means the seed should be ripe. The flat seed is definitely not good. The plump ones, if good, will not collapse in with a little bit of pressure. If they collapse, they are no good. If it seems like a great quantity of the seeds are not viable, that flower didn't get good pollinization for some reason. I've collected seed heads from my coneflower and had some heads seem like not a lot of good seeds were there, and other times lots. Maybe the weather was bad when that particular flower bloomed?
If you, or a neighbor, have other coneflowers nearby, they will cross pollinate. So that would definitely lower you chances of getting seedlings with the Orange Meadowbrite coloration.
Remy

The plump ones seem good and firm, so maybe I do have a few viable seeds. I figured the flat ones weren't any good, but I was hoping someone would tell me I was wrong.

My next door neighbor does have some purple coneflowers, so I guess they could have cross-pollinated, which means mine would probably revert to purple? I guess we'll see what happens. :)

Thanks, Remy.

From what I've heard, you won't get an "Orange Meadowbrite" from an "Orange Meadowbrite" seed, regardless of cross pollination or not. Same goes with all of the new pretty echinacea hybrids. But, it doesn't hurt to try ;)

I just traded for some orange meadowbrite seeds..so i guess to make sure you get the mother plant color you would have to do divisions or cuttings..has anyone tried to take cutting from any of the hybrids??

I've had "Mango Meadowbrite" for 2 years now, and it's nowhere close to being big enough to divide, unfortunately. I'm not good with cuttings, so I wouldn't even waste my time! I did save some seed, and I'm going to experiment to see what I get. Someone else here on GW had tried with one of the new hybrids, and had gotten purple...