I like blue + purple or blue + pink together! purple + pink is nice looking too! then again, I also have a space themed town, which might have something to do with that lmao
I love putting pink lillies with white and violet violets~ I also like using the 'black' flowers, like lillies and tulips with orange cosmos. Blue pansies and white tulips look so serene together and my "dark forest" area has purple pansies, whitr violets, black tulips and Jacob's ladders dispersed randomly throughout. It sounds crazy but they looks so nice together!