I'd like to hear about this too. 😀

I don't grow many super dark ones.

Here are a few of the darkest I grow. There are blacker ones on the market, but I don't have any experience with them. Afternoon shade might be a good idea, but the ones I post are all growing in full sun and seem pretty sunfast in my west central Indiana garden.

Hey Soul Sister is the darkest we grow, but it has two faces. Sometimes it has a grayed smoky look with a dark eye. I'm sure this is weather related, but it is not fading.

Edward Abbey is a deep purple with a wonderful watermark. It is also a vigorous grower.

Ebony Jewel is an older one and not one of the blackest. It is a reliable grower.

Serena Dark Horse is a deep red toward black. It is very vigorous and reliable.

The last two are our intros. They are both wonderful growers with a flower that is pretty sunfast.

Elderberry Wine maybe not as dark as you are wanting.

Witch King of Angmar is a little darker.

Some other notable near black ones are Africa (reputed to be one of the blackest), Ashwood Dark Side, Back in Black, Black Fury, Black Panther, Caribbean Frank League. I haven't grown any of these so I don't know how they perform or hold up in the sun.

I hope that helps.

Nancy

Most of the dark ones I've grown are growing in full sun and don't seem to fade. They are

Black Panther

Men in Black

Soli Deo Gloria

Debra

Very nice! Thanks for posting those photos. and especially since they keep their color in full sun.

Seedling