dj,

It's pretty straightforward - basically it's just which part of the image the color balance adjustment will affect - i.e. the dark bits, most of the image, or the very bright bits.

You may find it easier to work with the RGB curves - set the view to 'RGB Parade' - and then flip backwards and forwards between the two things you are trying to match - start off by getting the bottom of the of R,G and B in the same place in both shots (only adjust one of them) - then adjust so that the tops of the graph match. Once you've done that you should be pretty close.

Use the 'master' curve to add or remove contrast by making the middle curve up or down.

Goodluck.