Donahue's describes it as petunia red as well. I would tend to believe them, as they're a specialist in clems.

Let us know and post a picture, I'd love to hear the result

Here is a link that might be useful: link

I have Vino. It comes out red in early spring but the blooms soon start coming out with a pink cast. In my garden the only clematis that stays red is Texensis.

Katie