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Force RGB Color Space over HDMI?

Does anyone know how to force RGB over HDMI on a Macbook Pro with Retina Display. This is driving me nuts, as I have two U2410's. One is connected via DVI (using the DVI thunerbolt adapter), whilst the other is connected via HDMI. The monitor connected via HDMI negotiates the YpBPr color space, whilst the DVI monitor uses RGB. This makes it impossible to get the two monitors to produce the same colour. I can set the monitor to RGB within the OSD, but that just produces a mismatch of green and purple colours - in other words, the signal coming from the mac is still YpBPr so obviously setting the monitor to RGB ruins the colours completely.


There must be some driver setting or something to force HDMI to output RGB instead of YpBPr. Through Googling, it seems this applies to pretty much any Mac with a HDMI port, hence it's got to be a software issue, that's why I chose this forum. I'm about to duck home (I'm at work) and grab one of my HDMI -> DVI cables to see if that provides a work-around.


What happened to Mac's being a professional device. Surely they can't claim superior colour management if something as fundamental as the monitor's color space can't be controlled.

Posted on Sep 11, 2012 5:36 PM

Reply
11 replies

Sep 27, 2012 12:25 PM in response to Wardrop19

I have given up trying to use a Mac with a Dell or Samsung or Viewsonic monitor. Just ordered and received a StarTech.com DP to miniDP cable and was disappointed to see only YpbPR being output to my 22" Dell monitor. This is on top of the general fuziness and inaccurate colors. I've tried all sorts of other cables and adapters, both Apple and 3rd party, and the plain sad fact is that none of them work properly.


I plug in an old Cinema Display or a new Apple LED display and it works perfectly, colors look great, type isn't fuzzy.


I boot into Windows 7 on the same Mac using Bootcamp and my Dell monitor works perfectly.


It's OSX's display drivers that just don't play nice with Dell or Samsung or Viewsonic monitors. There's no other explanation because every other combination has problems with OSX and non-Apple monitors.


I can get into the long description of every possible adapter and cable I've tried (as well as the terminal command to adjust font smoothing). If I want the type to look right and the colors to look right, I just have to use an Apple monitor, which is aggravating as I have plenty of larger monitors here at work that I'd rather use.


Brief summary:


Three different MBPs, one a Retina display. Four different monitors from 3 different manufacturers, each with various connection options (HDMI, VGA, DVI, DP). DP to miniDP cable, DVI cable with Apple DVI to mDP adapter, HDMI to DVI with mDP adapter, couple of other similiar combinations of cables and adapters.


Bottom line is that all the screwing around produces a low quality, poor color accurate picture when the MBPs connect to 3rd party monitors. Plugging in the MBP to an Apple monitor (as old as a 2006 era Cinema Display) using any combination of adapter or cable looks great. Plugging in Windows 7 machines, either a dedicated Dell laptop or the MBPs in Bootcamp mode, all monitors look great. Also note that in OSX, the signal recevied by the monitors is YpbPr, but the same laptop in Bootcamp Windows 7 outputs RGB.


Hence, my guess that OSX display drivers are wonky except when plugged into an Apple branded monitor.

Nov 25, 2012 6:24 PM in response to Wardrop19

I'm bumping this because I also have the same problem. This seems to most definitely be an issue with Apple's drivers. If you go into your Utilities folder, open up System Information and go into the Displays setting, you'll find that while a monitor is attached with HDMI, there's an extra line that lists your monitor as a television.


I have two Dell U2410's, one attached via a mini-DP to DVI and one attached via HDMI. This is what I get:

DELL U2410:

Resolution: 1920 x 1200 @ 60 Hz

Pixel Depth: 32-Bit Color (ARGB8888)

Display Serial Number: XXXXXXXX

Mirror: Off

Online: Yes

Rotation: Supported

Television: Yes

DELL U2410:

Resolution: 1920 x 1200 @ 60 Hz

Pixel Depth: 32-Bit Color (ARGB8888)

Display Serial Number: XXXXXXXX

Mirror: Off

Online: Yes

Rotation: Supported


Now because of this I'm getting different colours between my monitors, and I can't exactly go out and buy another mini-DP adaptor because I'm using the other Thunderbolt port for actual Thunderbolt devices. However, I'm sure there must be a .kext or .plist file somewhere that could be edited to change the HDMI output to "Television: No" but unfortuantely, I know next to nothing about editing them! Perhaps someone here who does can lend a hand with that? I'm sure it's worth a shot.

Nov 28, 2012 12:37 AM in response to Wardrop19

thunderbolt in MBPs do not seem to behave well with Dell ultrasharp series. http://en.community.dell.com/support-forums/peripherals/f/3529/p/19458525/201488 89.aspx


I have a U3011, and my MBP retina 15inch
(10.8.2) only sends YPbPr space to the display via miniDP to DP cable instead of RGB. If I change the settings to RGB, the color is all funny looking. For all professional purposes this is useless. Nobody from Apple or Dell is willing fix this.


U3011 only uses HDMI 1.3, so you won't get the full resolution. I also have used a mini-DP to dual-DVI adaptor. It gets RGB from MBP, the text is all garbled for anything above 1600x1000 .


The System information tells me that MBP thinks U3011 is a television!! (Television: Yes, in the display/graphics section)


I am at my wits end.

Nov 28, 2012 9:28 AM in response to aramjam

Note that I do not have a Thunderbolt MBP and my problem extended to other monitor vendors, not just Dell. As I wrote above, OSX + Non-Apple monitor produces an image that was poor quality with poor color. It wasn't unreadable and it wasn't like green turned blue, it was just "off", and tiring to the eyes.


Same combination with same laptop running Windows 7 in Bootcamp looked fine, as per my message above. It's a shame as I have several 24" P2412 monitors available to me but I'm stuck using a slightly dim, circa 2006 20" Cinema display because that's the only monitor in the office that works properly with my MBP.


My consensus is that there's something simply wrong with the display drivers on my MBP in OSX, because the same video card using Windows drivers in Bootcamp mode look and work fine with any monitor.

Dec 4, 2012 10:45 AM in response to Wardrop19

I recently bought a new mac and found the same issue with HDMI display to my monitor. As everyone confirmed here, my monitor says that HDMI sends YPbPr to the monitor instead of RGB. If I use DVI connection, the color is back to normal.

If Apple puts HDMI port in their system to be used as general purpose display, they must fix this issue. I don't think there is any notice that mac's HDMI port is designed to work only for Apple cinema display! And as plochner found, it is not an HDMI limitation but just a software compatibility issue. Where should we report this problem to Apple?

Jan 31, 2013 8:13 AM in response to Wardrop19

This hack seems to work. It isonlyfor U3011. I can confirm that it works:


Resolution: 2560 x 1600 @ 60 Hz

Pixel Depth: 32-Bit Color (ARGB8888)

Display Serial Number: ******

Main Display: Yes

Mirror: Off

Online: Yes

Rotation: Supported

Connection Type: DisplayPort


MBP earlier reported this as Television : yes and did not work if i had sent the color input as RGB.

Jul 3, 2013 4:08 AM in response to aramjam

There is a more general approach for creating an override file:


http://embdev.net/topic/284710


Note the original solution is for a specific monitor, but deeper into the thread there is a ruby script.


You can get instructions for using the script, and just a sprinkle of apple bashing:


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

Dec 17, 2016 11:14 AM in response to Wardrop19

My wife has just got a macbook retina 12" 2016, and i hooked up a USB-c HooToo interface, with HDMI going to an external Dell 24" monitor. I had been using the Dell with no problem with my MacBook Pro, and calibrated it with a Spyder5 with no problems. great image and colour.


When I connected the new macbook, horrible image etc, text awful and haloed in white.... Turns out it was outputting TV standard signals, not RGB.


Having read all of the threads relating to this, I thought I'd try an HDMI to DVI cable first, rather than messing with forcing the mac to output rgb, in case we wanted to use the machine on a TV at some point.


Glad I did, works like a charm. Back to a splendid image, no need to mess with the system software, and all with a nice gold plated cable from Amaz(ing-)on for £4.99

Force RGB Color Space over HDMI?

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