I'm also really in love with real red, emerald envy, and lemon lime twist for Christmas! I wasn't sure about lemon lime for Christmas but I think I'm sold! You can also mix metallics! I used copper for my bow and gold for my pinecone!
I also think black and white Christmas cards could be quite elegant!
Which camp are you in? Will you be using black on Christmas cards? If not, I hope you'll be inspired to try!