Q: Horrible colors on external monitor using macbook air(2012) with mini dp to hdmi

I had exactly the same problem, and in my case it was an easy fix. OS X thinks my monitor is a TV, and is using the YCbCr colour space rather than RGB. I had to override an EDID setting to force the RGB colour space, and it is now working correctly.

Here's how to do it:

http://ireckon.net/2013/03/force-rgb-mode-in-mac-os-x-to-fix-the-picture-quality -of-an-external-monitor

I blast Apple a bit in my post, but as some others have said, perhaps 10.8.3 fixes it. Even if it does, it still took far too long.

So tweacking the OS X did not solve the problem like written in previous threads? So what should I do? , try to tweak the OS X of my new machine. I don't think this is a good idea.

I have waited for a very long time now and apple did not come with a solution for this problem. Want to know why?

They have told me that I should buy an external apple cinema display instead of the thirth party screen and it should work flawlessly according to the Apple "genius".

But I don't have another 1000 euro to spend on a cinema display.

This is the exclusivity and policy of Apple. Just like the appstore. App's will only work on mac devices.

Waiting for the update could take a long time and would it be fixed after all?

So I will wait for another to test the tweak and when it works fine, I will have to do it myself on 2 macbook air we have when working with an external display of Samsung (150 euro)

Cheers.

Thank you very much! I've tried to solve this problem since September, when I just received my MacBookPro. Finally, I can reuse my Samsung monitor without washed colors and with a true and deep black! For your information I use an adapter Thunderbolt (Mini DisplayPort) – HDMI, and I'va backed up the folder replaced with the one created by the script, in order to test if OSX 10.8.3 fixes the problem.

Thanks a lot heycoatch. That worked perfectly. Now colors are back to normal and I finally have audio as well!

Great tweak, this worked for me!!! Now my hdmi adapter is back .

It's unbelievable that Apple didn't fix it.

Thank you so much.

Thanks for the post coach!

Worked perfectly fine for me!!

Yay this has fixed the color problem for me!! but now, my highest resolution option is only 1360 x 768 anyway to enable higher resolution options for me? But for sure, this fixes the color problem, I can finally see grey again!

Apple should have fixed this long ago, its a shame

I finally fixed my problem by getting rid of my tv and buying a completely different monitor. Now i can finally do 1080p without any color issue

So does the 10.8.3 Update fix the problem or is it still there? I am dreading having to wait until 10.8.4.... or 10.9!

No idea, and I just arrived at work. When I get home, if nobody has replied I'll undo my changes, test it out, and let you know. If it fixes it I'll update my workaround blog post.

In my case the problem is solved with the 10.8.3 update!

I hope this fixes the issue. My question though, I used heycoach's fix by installing that profile tweak. I wonder if I need to uninstall it after the update to ensure its working properly?

I just bought a MBA 11 a couple of weeks ago and struggled mightily with this problem.  After a week of trial and error, for me the answer was to go the DVI / VGA route (instead of HDMI) connection into my LED TV monitor (1360 x 768).  It is pretty much crystal clear now.  I was on the verge of taking a full refund had i not resolved this issue.  I was getting horrible headaces due to eye strain via HDMI.  Not sure if 10.8.3 will solve the issue (can see it is available just today) for HDMI; will try that later.

Confirming the problem solved on my mid-2012 MacBook Air with 10.8.3 updater - FINALLY!!!

It's been a long wait, but I am very glad the issue has finally been solved!