Monthly Archives: November 2014

Whacky Colors on Projector from MacBook Pro

I was doing a Keynote presentation recently, and had a problem with colors on a projector attached via a Thunderbolt-to-VGA adapter connected to a MacBook Pro. The first few slides in Keynote looked fine, but the first slide which contained a color photo, the colors in the photo were scrambled — sort of like a color negative. The black, white and gray on that slide and the on other slides looked fine.

I tried two different projectors and three VGA cables and the problem remained the same. The problem was also not just Keynote. It was any color image, including the default Mavericks desktop background (the wave). I think Keynote was actually masking the problem because my slides were mostly gray scale.

I was playing around with the color calibration controls (System Preferences/Displays/Color), in a desperate attempt to fix this, when the screen faded to black. When it came back, everything was fine. I didn’t think I had done anything which should be expected to fix anything that weird.

I had also lowered the screen resolution which didn’t seem to have any immediate improvement.

I failed to get a photograph of the problem. If anyone sees this happen again and can take a photo, I’d like to see it. I have reported this to Apple via feedback. It sounds very similar to a problem people were reporting back in about 2010.

I see no reason this wouldn’t happen on any other external monitor besides a projector.

[Edit: If you give public presentations in front of groups, you should have some color on your warm-up slides so you can notice if the projector colors are bad before you get into the main part of your presentation. Having a color photo on the first slide would have helped. ]