I can't believe that no one has answered your question yet! I was originally going to say that I don't use blue all that much in making Christmas cards, but when I went through my gallery to see if I could find some examples for you, I discovered that I use it quite a bit! Here's what I found:
Cards for Becca (the one on the right uses navy)
Freezin' Season (combined with purple)
Cool Yule Palette (combined with kraft)
Pretty in Pink (combined with pink, obviously)
Missing You at Christmas (lighter blues)
Acrylic Paint Snowman (navy)
Sparkling Snowfall (with pink, again)
Dasher Has a Blue Christmas (with black and silver)
Santa Collage (Faded Jeans distress ink)
Happy Holiday Tree (with green and gray - it was a color challenge)
Maybe that'll jump start an idea or two for you!
blue christmas
