Strange clematis flowers

Last year, I planted a new clematis (forgotten name just now) which is a lavender colour with a red bar, in a very large barrel with a Gertrude Jeykll rose. It flowered lovely and, earlier this year, I pruned it as instructed on label. New flower buds appeared and when the first one opened - oh!!!  The flower appeared rather curled and wizened at the edges and is maroon in colour - so are the ones now appearing. It should really flower later on  in the season but - why has this happened?? The rose is healthy and so are the clematis leaves, and I added feed earlier on and have watered in the dry weather we've had here. Is it a result of the late frosts?  :blink:

We have had issues at work with a new variety called rebecca which is supposed to be deep red, but has come out maroon/ purple. 

The grower has blamed a cold snap just as the buds were forming and customers who came to complain earlier in the season are now saying their plant is starting to bloom in the correct colour now.

Might be worth cutting off the flowers you have and see if it buds up again.