I think it's unlikely to be a problem with the RAM. Is this an HDLink connected between the Eizo monitor and a DeckLink card?
The description of it as negative makes me think it could be a dual-link SDI problem. Maybe if you were using dual-link SDI it might be only displaying one channel. In which case, please check both SDI cables.
If you are not using dual-link, maybe the output from your Mac is set to dual link. If you have a DeckLink card for example you can disable dual-link in the Blackmagic section of System Preferences. If using FCP7 Please check the settings under View->Video Playback. If it's set to an RGB codec, try changing it to YUV.
If using an HDLink will also have Lookup Tables which you can apply to it's outputs to change it's look. I would suggest connecting the HDLink to a computer by USB, and launch the HDLink Utility, and press the 'reset unity' button. This should clear any possible bad colour settings.
If you still have problems I would suggest contacting support to troubleshoot the issue further.