I have a standard magpie buck and a self chocolate doe. What color would this bring about?
Your magpie buck is a chinchilla harlequin (harlequin <ej> with an allele in the C position, <cchd>, that blocks expression of yellow pigment, leaving the rabbit in shades of black and white). Most harlies/magpies are agoutis <A_>. He also is a black, which is dominant <B_>, and dense colored rather than dilute <D_>. He may or may not be broken, since that tends to be masked by the magpie coloration. But you can see clues that he's broken by noting a complete absence of color on his feet and belly, though that's not a 100% accurate clue.
Your self chocolate doe is doe is a recessive self <aa>, recessive chocolate <bb> and dominant full-color <C_>, and sh is not broken colored so she's <enen>. She is full color and not dilute, harlequin or tort, so you know she's <C_> <D_> and <E_>.
What you'll get from this cross depends entirely at what the two rabbits are carrying in their undetermined "second places" (the dash after the dominant allele, for instance <B_>).
If your buck carries a self or tan allele hiding behind his agouti, <A at> or <Aa> you might see tans (aka otters) or selfs in the litter. If he does not and is homozygous for agouti <AA>, all the kits will look agouti but carry self, i.e. <A a>.
If your buck carries a chocolate allele hiding behind his black, <Bb> you might see chocolates or chocolate agoutis in the litter. If he does not and is homozygous for black <BB>, all the kits will look black but carry chocolate, i.e. <Bb>.
If your buck is broken you should see, on average, 50% broken colored kits in his litters.
On to the doe... since she has many recessives, the only bits at issue are the C, D and E gene series.
If both rabbits carry a hidden dilute allele <d>, you'll probably see dilute kits (blue or lilac).
If she carries any of the lower C series alleles (cchd = chinchilla, cchl = sable/shaded, ch = himalayan, c -= REW) behind her full-color C, you might get chinchillas or sable chinchillas, as well as sables if the buck carries cchl, ch or c; or himis if the buck carries ch or c; or REWs if both she and the buck carry c.
If she carries harlie <ej> or non-extension <e> in her second-place E, you'll very likely get harlies or magpies (which are agoutis), possibly torted harlies or torted magpies (which are selfs), and depending on what the buck carries in his second place E, possibly also REWs.
So even though it's hard to predict exactly what you'll get from this cross, what you
do get will probably give you a lot of information about what genetics your rabbits are carrying, which will make predicting future litters (with these two, or other pairings) more straightforward.