You know how I love my blues! Fall is usually associated with warm tones, reds, oranges and golds, but blues and teals work just as well with the fall season because they are complementary to the oranges of the season.
Complimentary colors are those opposite each other on the color wheel. as pictured to the right. Using complimentary colors makes your color scheme really pop. You can use any shade or tint within that color family (i.e. dark rust with either deep teal, light teal or muted grey blues)
I love the way the blue of the boots adds a sense of drama to this otherwise neutral toned bouquet. The darker shade gives it a restful feel. Compare that to these bright turquoise vases filled with fall leaves which creates a sense of whimsy.
Hopefully this will inspire your use of blues this fall.