The Black offspring Chris09 mentioned though will actually be black with a golden breast and neck.
The White offspring are as mentioned though - Similar to Red Pyle in which they are white with a reddish gold breast and neck.
There's a thread around here on crossing an Australorp with an Orpington - That's the color you'll get if the White is recessive.
Also, keep in mind some Orpingtons carry dun, which means 50% of your offspring might end up a chocolately or dull black color instead of a shiny black.
The White offspring are as mentioned though - Similar to Red Pyle in which they are white with a reddish gold breast and neck.
There's a thread around here on crossing an Australorp with an Orpington - That's the color you'll get if the White is recessive.
Also, keep in mind some Orpingtons carry dun, which means 50% of your offspring might end up a chocolately or dull black color instead of a shiny black.