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At my place of work, we have several different video projectors, but they all use DLP technology, and the colors are wrong: for instance, yellow looks more like green, and all other colors are similarly distorted. Any kind of presentation or collaborative work is hindered by these wrong colors.

On the laptop screen, the colors are fine but on the projector (hooked up via normal short VGA cable, and showing the same image at the same time), the colors look wrong. This is not about one specific projector or one specific laptop; it seems that any combination of projector + laptop has the exact same problem. Every VGA cable appears to be intact, so a cable break could perhaps be ruled out.

Someone said that DLP is poor technology, but that's not true. I'm using a DLP projector at home (regular PC connected via HDMI) and the colors are excellent. Still, there's some kind of curse on the machinery at work.

How can we get decent colors?

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Here are a few samples. OK: NEC NP61, HP mp 3135. Bad: NEC NP60. Now the question is, what does this indicate? I've googled reviews for the bad NP60 and they are all excellent (generally 4.5/5 stars and not a word about poor colors.) – Torben Gundtofte-Bruun Apr 15 '10 at 13:07
Business-class projectors are usually designed for maximum brightness at the expense of color accuracy, while entertainment-class projectors are more heavily tuned for color accuracy. – rob Apr 19 '10 at 19:21
Color accuracy is one thing, but when yellow is green and grey is white, your PowerPoint slides and Excel data look really bad... – Torben Gundtofte-Bruun Apr 21 '10 at 18:26
up vote 1 down vote accepted

I went through every setting in the projector's built-in menu to see if there were any settings that had stupid values. Indeed, there was one called "Brightness" that someone had turned up to maximum in the futile attempt to increase the lamp's brightness. The result was that the colors were completely washed out, as described in the question.

By restoring all projector settings to reasonable values, the affected projectors now show the colors just fine! (The silly brightness setting did 99% of the trick.)

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I wonder if the projectors are expecting a component (Y Pb Pr) signal instead of the VGA RGB signal. This page notes (in the section about portable projectors) that the projector will often re-use the same VGA-type connector for both signal types. Maybe you can find a configuration setting on the projector to tell it that you're connecting an RGB source instead of a Y Pb Pr source?

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I'll take a look in the projector's settings next time. But wouldn't the default setting be to treat the VGA port as a getting VGA signal? It would strike me as odd that various makes&models all default to component. – Torben Gundtofte-Bruun Mar 26 '10 at 14:19
Maybe, I'm not sure, but you seem to have eliminated any source of hardware faults. The thread below suggests that some projectors will switch to component if they think the resolution looks like a video source. Note that the setting you're looking for may refer to "color space". – coneslayer Mar 26 '10 at 14:53
I can now definitely rule out the Y Pb Pr source. The unit only accepts and understands s-video and VGA. – Torben Gundtofte-Bruun Apr 1 '10 at 14:32

I've seen some DLP projectors that use a prism to get their colors, and others that use a spinning color wheel (picture something like 3 stage light color gels, usually R/G/B, as thirds of a spinning disc). I've found that the ones that use a prism tend to have extremely good color fidelity, and the ones that use a color wheel tend to be crappy.

Have you looked at online reviews for the model(s) of projector(s) at work and seen if other uses mention crappy color fidelity? It might just be a poor quality product. We had a cheap small portable projector at work for a while, that wasn't even DLP, that had really bad green/yellow issues. It turned out to just be a really poor quality product, even though it was from an otherwise reputable brand name.

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I believe my Acer H6350 at home uses a color wheel, and its quality is excellent. So I wouldn't expect color wheel'ed units to be crappy by definition. – Torben Gundtofte-Bruun Apr 1 '10 at 14:34

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