We had one yesterday that blew one of my color theories all to pieces. My daughter has a Paleface out of our "Old Blue" cow (Book Em' Dan'O x Lim x SH), she's a black baldie with just a little roan on and under her tail (her mother was a nice, even, frosty blue roan). Last year (first calf) she had a blue roan out of an Angus bull, so I bred her back to Jakes Proud Jazz and assured my daughter for the last 9 months that she was going to have a blue roan (yeah, I know it wasn't a sure thing, but it seemed like a safe bet) or maybe accidentally a black and white paint. The cows mother and sisters have been bred Shorthorn several times and never could turn any of them back red. But this one manages to have a red and white painted up baldie... Actually looks pretty cool, and he's a nice one, too, so it's all good, just not quite what we expected.
Like the others said, you could get anything from solid blacks to roans, paints, whatever. Every calf will be kinda like unwrapping a Christmas present, you might think you know what's in there, but 'til you get it out, you'll never know for sure.