Sometimes I like to plant together 3 or more annuals with blending pastel colors.
For pastel blending: One of my favorites is pink wax begonias, ageratum and dusty miller. Also like lavender, pale yellow and apricot blends.
I also like bright contrast - yellow, red and orange - a number of annuals fit into this category.
What about the rest of you gardeners? What do you like?