Question
What type of flowers come in purple and will mix well with an arrangement of orange roses?  

Answer
Hi D

I love that colour combination too!

You can get Lisianthus in deep purple, that would be my very first choice as they are such beautiful flowers and such a deep purple.

You can get Calla lilies, although the colour always seems a bit flat/dead.

Anemones are superb, Trachellium interesting with its fluffy mounds, Freesia, although more lilac than purple.

Hope this helps.

Regards
Sue
p.s I am based in the U.K.