I have some cream with yellow center mums in a pot with violas that are bluish- purple/yellow/white. This is a fall/winter combination mostly, but so far it is still looking good so I'm keeping it until the violas fizzle out in the heat of summer. This doesn't help you now, but since mums root so well from cuttings it might be a good idea for the fall.

I just bought a veronica in a deep purply-blue that I think would be great with anything yellow or cream.

Lorrainey2k,

Great idea! I will try the violas this fall. Maybe I can locate the veronica now. I recently saw a large container with yellow mums, blue salvia and trailing white lantana - very pretty. Thanks for replying.