I was hoping it was a picture of both Candidates, that is a real problem.

Probably something melting inside from a third party replacement bulb. Some of those cheap bulbs lack an infrared filter that prevents over heating.

I have seen this problem countless times on LCD and LCOS based projection displays both front and rear. It's a problem with the LCD panels/polarizers and there is no way to fix it without replacing the entire light engine which is cost prohibitive. I've seen this happen to Sony, Epson, Mitsubishi, Sanyo, and others. It is often caused by lack of maintenance, specifically cleaning, which causes poor airflow and heat damage.

Does anyone remember the Sony green blob issue with their SXRD TV's? Sony lost a ton of money on that fiasco but at least they were nice enough to repair the sets. I worked as an installer for a shop that is also a full service repair center for just about any brand and I remember picking up those Sony sets at least a couple times a week for months.

It looks like magnetic interference.

Don't think that impacts non CRT projectors though.
Or is it a CRT projector with a big speaker sitting next to it?

The most likely culprit is actually the aging of the LCD chipset color elements (assuming someone didn't totally mess with the color balance). This tends to become very noticeable around 5000+ hours...but every projector is different.