View Full Version : Colour Management in Firefox

06-20-2008, 07:18 AM
I came across this post on another forum:

#1 Type about:config in Firefox 3's address bar and press Return. The configuration settings will appear.

#2 In the Filter field, type gfx. The list of settings will shorten to show just those related to graphics, ie gfx.

#3 If the Value for gfx.color_management.enabled is False, double-click anywhere on that line to toggle the setting to True.

#4 Quit and relaunch Firefox 3 and you're in business. You can confirm that colour management is working by viewing the photos on this page. (http://www.color.org/version4html.xalter) If all four quadrants of the first photo are a seamless match, then colour management in your copy of Firefox is up and running.

Not being anything approaching technically minded, I thought I'd post it here as it might have some relevance to us in terms of colour matching - but I would be grateful if someone more technical than myself could explain what the advantages are.

As a side note, the brown frame around my avatar is invisible on my computer at home (running Firefox) but is a slightly different shade from the brown background on my computer at work (running ie 7) - I simply cannot understand why this should be the case - but gave up worrying about it a long time ago!

06-20-2008, 08:10 AM
Ok, So I get the bottom image of the photo (Green Sky Upper Right and Lower Left), but damn if I can figure out what to do to fix it :(

06-20-2008, 08:10 AM
It can make a huge difference but you will see it the most when printing stuff. Most apps dont take heed of colour correction data in files. The one that I know does is the Windows Picture and Fax Viewer. I would imagine that Acrobat does also given that most print shops will do a proof in PDF.

I dont think any app I know embeds color calibration into the files. Maybe photoshop would and I have some tools to do it but generally you just get RGB data. Really, the graphics card should be doing the color correction for the video card + monitor all at once but that corrects only for the display device not the image.

I would say this though. Its a bit of a tech minefield the last time I looked into it.

With my Firefox 2 I get the same as Neon - the bad version. If I use Picture and Fax viewer then I get the ICC2 ok but not 4. Using Acrobat I get them all - as you might expect from an Adobe program. I guess FF V3 will do all of them too now.

06-20-2008, 09:13 AM
But what is it doing? Can you explain it in plain English? I don't even understand the problem it's trying to correct!

as you can see I'm VERY thick when it comes to these things!

06-20-2008, 10:28 AM
Color Correction is a complex thing indeed. Its best used when you do a lot of printing...if your monitor and printer are not calibrated then what you see on screen will not be what you see on print. ICC profiles are used to make the two match I believe.

NOW...I know this is a neato cool factor thing that is great at first...BUT...I tend to hang out at 4chan (the dark deep cess pool at the end of the interwebz) and they have an HR board that occasionally has some good HR stuff if you can get past all the perverted stuff...and turning on ICC color correction will slow down the display of high resolution images a LOT...especilaly if yo uopen multiple HR images in multiple tabs...

So if you don't plan on printing images FROM your web browser and you like HR images, I'd recommend against this setting. Otherwise its cool.

06-20-2008, 12:36 PM
The realness or correctness of colours is usually expressed in terms of warmth and shade. How much yellow in green etc....

The principle is that you start with a value (a subjective choice) and display that value on hardware that creates a new set of variations. Colour correction is usually centered around Monitors and Printing. Light behaves differently from pigment and differently from toner.

Different rendering engines can treat colour differently too (eg your IE example) Each of these differences can modify your colour.

Of course you may see colour differently than I do too. (Even spell it wrong :) )

Most graphics cards have a colour correcting function. ATI has one attached to its properties icon. Adobe has a colour correction routine too (I"ve forgotten where it is). I set mine once for the use of a medium, say the monitor, and forget it. If I were to publish a picture I'd review it for each project, especially with each change of printer\printhouse.

The thing is that because it's mostly an interpretation of base values and (with the exception of editors like CS2) you don't really influence those values - its sort of a wash. If your screen is set up to display reasonable colour the Firefox settings aren't really important. The only issue might be that if my colour settings were wildly different from the average, my creations would seem off on everybody elses computer because they were designed to look good for me.

IMHO Firefox is being considerate\'far sighted' with these settings but they probably aren't that important. Alot of interest is payed to how a browser renders a page. Comparisons are made and colour correctness might be a point of comparison.

Best thing is to set up your monitor and graphics card correctly than assume you're close to normal. "... gave up worrying about it a long time ago!"


Of course anyone with critical uses for these is free to pipe up.

06-20-2008, 01:39 PM
Of course you may see colour differently than I do too. (Even spell it wrong :) )

Yes, and thank you for providing the example of how to spell it wrong. :P


06-20-2008, 01:40 PM
OK, so it sounds like I don't need to worry about it, which is the important thing!

06-20-2008, 02:48 PM
Nope, you don't need to worry about it at all. And if you decided you did need to pay attention to the issue, just using software-based correction wouldn't be enough, anyway. You'd need a colorimeter to compensate for the inaccuracies of your monitor. Color management is difficult, expensive, and almost always unappreciated by whoever you're working for.

06-20-2008, 04:11 PM
Yeah, the above covers it pretty well. Basically each device in the whole chain involved in the image needs to be calibrated so that the next device sees the same as all the others. When the whole process is calibrated it is called a Color Calibrated Workflow. People who are magazine editors for example have to lay out the pages and then it gets sent to a printer. Its important that the printer prints what the page editor wants. Midgard has it right when he says that these devices need to be measured. You can buy colour calibrated monitors but they are hugely expensive compared to normal and they need to be recalibrated from time to time. When you use one your supposed to sit in a room with neutral coloured walls and spectrally even lighting to stop your eyes compensating for it. All commercial printers like the Heidelberg types have a known or preset colour capability. The image stores a color calibration profile which is a kind of translation setting for the image. To go from monitor to printer you go via a color calibration transformation for which the parameters are stored in this ICC content embedded in the image. Each device has a range of colours that it is able to display / print which is called the gamut. So going via this translation can render colours from a source into another device which it is unable to display. These colours are known as out of gamut for that device. So when creating artwork on an image editor like photoshop, I believe that you can set up the colour calibration to which the image is set for and then you can draw the image and photoshop will then know which colours are out of gamut for certain devices like Heidelberg printers. If that is the case then its advisable to change that colour on the image so that the printer can print it to the same color as you require. The company Pantone produces colour inks and swatches of known colour so that when you want this exact colour you can specify the exact way the printer should print that to get that exact colour. It ought to be possible to draw an image using just pantone numbered colours and get it pro printed and the result ought to be exactly what you thought it would look like without a calibrated workflow.

Basically for us don't worry about it. Only people like Gamerprinter and people involved in the print industry should concern themselves with it. But if you ever decide to get a map commercially printed then it starts to become important or else expect that the result will look a little different from what you saw on your uncalibrated monitor. It might have a brown hue or a green hue etc. When you get a digital proof back from the printer it WILL have an ICC profile in it and you SHOULD view it with a capable viewer but even then your monitor will not be calibrated. My old nVidia card was shipped with a pantone swatch and a program to set up the color to make the swatch match on the screen. Then the screen is somewhat calibrated.

Although I know this much I am not an expert in this colour calibration field and would like to know more. I have some tools to attach and correct images by attaching some colour profiles to them.

The website shows 4 images with ICC cal data embedded into the images. The raw colour values contained in the image can be very different from monitor RGB values unless you use the standard Adobe sRGB ICC profile. This web page has images with unusually extreme ICC profiles. If the image display program understands how to translate these ICC profiles then it can get it back to standard RGB for your monitor hence if not then they look very weird.

Its a useful page to test your imaging program. Save the images and load them in photoshop and I would very much expect them to look right and very different from what you saw on your browser.

Its a veritable minefield I tell you !

06-20-2008, 04:40 PM
I believe you!