I made a video last week with two cameras - both good quality consumer Sony video cameras  (an older Full HD HDR-CX550 and a newer HDR PJ790.) When I went to edit the separate clips one camera had a slightly different colour/light setting.  Does anyone have any suggestions for synchronising the two cameras prior to filming with them? Both cameras filmed simultaneously in identical light conditions.

0pps. That should be "balance"

I will check that out.  If I am able to do so, is 'white balance' something that is absolute in the sense that you can have identical settings on two different cameras? I have always relied on 'automatic settings' and this problem only became one when I noticed differences in the two clips shot in the same light conditions.

Typically, yes.  I'm more familiar with still photography rather than video equipment, but if you can set the appropriate color temp for the lighting you have set up (say 2900k), that should fix it.  If you don't have that ability, every camera should have a lighting type setting (halogen, tungsten, etc).  Set them to the same setting.  Since they are both sony cameras, they will probably be the same, but no guarantees. 

Camera manufacturers typically improve their white balance correction in auto mode with each new hardware release and each generation of firmware.  So your experience in the auto settings is completely normal.

I will check that out.  If I am able to do so, is 'white balance' something that is absolute in the sense that you can have identical settings on two different cameras? I have always relied on 'automatic settings' and this problem only became one when I noticed differences in the two clips shot in the same light conditions.

If your using the automatic settings then even though you have the same lighting because you have different camera angles it is quite likely that they will have set a different colour balance, even if they were the same model, because the scene has a different mix of colour. The cameras don't care that the lighting is the same they are looking at the scene not the lights.

If you want as close as you can get to the same colour balance then you will have to use a manual setting. If the cameras can be fixed from a colour target then use a neutral grey one.
 

Sony Vegas  Movie Studio HD Platinum 11.0. I looked at trying to fix the difference but it was all too complicated!! I am quite proficient at managing the clips, rendering etc.  I really need to do a basic photography course in order to understand white balance, hue, colour correction etc etc. If anyone has an interesting youtube link to these issues, it would be most welcome.

Color settings are intended to compensate for the color temperature of the light source. Back in the film days any film had a set color temp it was made for, and if the light was a different color temp than the film you had to filter the light either at the light source or at the lens (or get creative in the darkroom. Now in digital its so much easier. Here's a bunch of color temp info http://en.m.wikipedia.org/wiki/Color_temperature

Images like this help as well http://www.jgscraft.com/ledconv/color_temp.jpg

Fluorescents can still be challenging due to spectrum spikes from the gasses in the tubes, more so on film as compared to digital in my narrow experience with Nikon still cameras. If you're having challenges in that light environment that may be contributing if dealing with different brands or generations of sensors.

Never ceases to amaze me how the human mind so easily makes these color temp adjustments