I did a test on my localhost and didn't have any color distortion.
Are you using the latest version of databridge?
It uses the GD library in php to manipulate the images. What version do you have installed? You can check by adding code to a blank page and browsing it and finding the GD section:
My localhost uses:
GD Version: bundled (2.1.0 compatible)
FreeType Version: 2.5.5
libPNG Version: 1.5.18