I'm still learning so don't take my word for it, but if I understand correct it depends on what other genes the adults carry. I just got a little ry doe from a lilac doe, and a ry buck. I was thinking about breeding father to daughter when she's old enough and see what happens.
Technically she carries a/a (non-agouti/black) b/b (chocolate) D/d (blue dilutes) and got the E/e (recessive yellow) from her mother if I understand right, not to mention what ever else her mother may have had that I don't know about yet. Then her father is ?/a, B/?, d/d and e/e, and who knows what else.
So I would guess I would get more yellow than not, but maybe black, blue or chocolate thrown in as well if the buck has the right "a" and "b" genes, or even something totally random from genes I have yet to identify. Please anyone correct me if I'm wrong. Both also carry marked genes, so I imagine there's a chance I could get white color blotched mice too.