I've been on the hunt as to how to fix this problem with my Optoma HD25e projector. I'd experienced the same issue as I recorded here:
For me, I found a fix in my NVIDIA Control Panel which seemed to work as of v8.1.962.0. It's in the "Display > Adjust desktop color settings" area, the dropdown for "Content type reported to the display."
Change this from "Auto-select (recommended)" to one of the other static options - either "Desktop programs" or "Full-screen videos." This prevents applications like Media Player Classic or the Opera GX browser (in my case) from changing the color settings, which seems to cause some projectors to sort of re-detect their input.
If other people still have this issue and have NVIDIA graphics, give this a shot.
Hope this helps other folks out!