Color question

[Shaun Gibbs]

    My agouti and black pair just had a new litter last Friday!!  But I can't
figure out the color of some, I know there is agouti but this other color is
unfamiliar to me.  It's black on the top (back) and white on the bottom.  I
was thinking maybe it would be a gray agouti but it's too dark to be that.
Can someone help me out here?

Thanks
Shaun