You'll get agouti and black tans still! If you want to make a colour other than agouti/black tan in the first generation you need to choose a mouse with genes that will work with the chinchilla. These are the only four I can think of off the top of my head:
Chinchilla (A/at c[ch]/c[ch]) x Siamese (a/a c[h/c[h]) = 50% Burmese (A/a c[ch]/c[h]), 50% Burmese Fox (a/at c[ch]/c[h])
Chinchilla (A/at c[ch]/c[ch]) x Silver Agouti (A/A c[ch]/c[ch]) = 50% Chinchilla, 50% Silver Agouti
Chinchilla (A/at c[ch]/c[ch]) x Fox (at/at c[ch]/c[ch]) = 50% Chinchilla, 50% Black Foxes
Chinchilla (A/at c[ch]/c[ch]) x Chinchilla (A/at c[ch]/c[ch]) = 50% Chinchilla, 25% Silver Agouti, 25% Black Fox
Hope that helps!
Sarah xxx