rather than relying on DBE to fix the balance, you can do BackgroundNeutralization (followed by ColorCalibration) to fix the colors. when doing BN, make sure to set the threshold high enough that the (higher valued) green pixels are considered by BN or else the results will not be as expected. or, you can use PhotometricColorCalibration to do it in one step, but you still need to configure the background threshold.
of course, if you have bad LP gradients, you can use DBE first and as a side effect it will mostly neutralize the background, but it's a good idea to do some sort of color calibration step after DBE.
rob