I believe that the color red distinctly compliments the color of champagne for a wedding. Red also shows passion and love. It is a crisp opposite to the warm inviting honey color of champagne. I have recently attended a wedding with red as one of the main colors. The red wend very well with everything.
I would have to say that brown and rich colors are good. Also a variety of dusty pinks. For a good spectrum of color add white and eggshell - it will give depth but it wont be too flashy with the addition of bold colours