Here are data and wire colors for some unipoloar stepper motors. If you have data for additional models, please contact the author.
Parallax P/N 27964
12V, 90 ohm, unipolar, 5 wire
Wire colors: BK=common, WT=Coil1, RD=Coil2, GN=Coil3, BR=Coil4
Some 8-wire stepper motors made by Airpax have a top bundle of four wires and a bottom bundle of four wires. Connect the two yellow and two gray wires all together to form the common. The remaining four wires are the coil wires: top red = coil 4, bottom red = coil 3, top black = coil 2, bottom black = coil 1.