PM Security Validation Backgrounds

Mendel

I understand why a Security Validation is needed on a PM, but why does these have to have such harsh backgrounds?  The color schemes on many of the backgrounds simply makes it next to impossible to see the letters at all (many end up being black letters on a black background).  The few times I've sent a PM, it takes at least a dozen, if not several dozen, attempts to get a visible Security Validation code.  Could there be some way to disable the background, especially for visitors who are visually challenged like myself?