To correct for reverse polarity, please remove the plug from the input socket of the ballast, flip the plug and re-connect it. The HID bulbs should now turn on. If they don't, you may have a fuse that is blown; if so, please replace the fuse then try the HIDs again.
Having connected to the ballast with reverse polarity did not do any harm to the ballast. As mentioned above, it is possible for the reverse polarity situation to pop a fuse.
Flipping the input plug to the ballast usually means that the clips on the plug will not be used. The yellow gasket on the plug will hold the connection but feel free to use electrical tape as a secondary means of securing the connection.
Reverse Polarity is common for Chevy's and Honda's and has been reported for other vehicles, too. Some vehicles have reverse polarity for one plug and not the other.
At times, a High/Low harness can have an input plug wired in reverse. This situation can be treated as a matter of "reverse polarity" such that flipping the plug 180 degrees will solve the problem.