I can see this has all been planned with precision.
Going to look good next year. :o)

What is the small dark-coloured plant?

we'll see terratoonie, maybe I'll put new photo in next july when its in full bloom, this is the acid test because I have never been in a position to plant an entire border in one go before I don't expect it to be perfect but I have been able to try and match plants :o)

looks good to me Johndman!