The three grapes used in Champagne are Pinot Noir, Pinot Meunier, and Chardonnay. Pinot Meunier is a black grape that is closely related to Pinot Noir, but is pretty much only used to make champagne. You might be surpised to find out that two black grapes are used to make a white wine, but champagne is the exception. The skins do not come in contact with the must, so therefore no color is leeched ino the wine. Pinot Noir is used to give body and aroma to champagne. Meunier gives it an extra kick of fruit, and chardonnay adds finesse and elegance. Here is a list of the different districts of Champagne and which grapes they tend to use:

Montagne de Reims: Mostly Pinot Noir

Vallée de la Marne: Pinot Meunier

Côte des Blanes: almost all Chardonnay

Côte de Sézanne: Mostly Chardonnay

Aube Vineyards: Mostly Pinot Noir