Understanding Color: Part 3, Color Space and Color Profiles

So by now you know that you can adjust the color with some basic software controls such as Hue/Saturation, and Color Balance. Hopefully you also played around and found Photo Filter, Curves, and Channel Mixer. And you also saw that you could adjust the color depending on your camera’s White Balance settings related to your light source, matching the light source to get as close as possible to what you see, versus mixing the WB and the light source up on purpose for artistic effect.

I urge you to use any of these controls with artistry, with some subtlety related to the intent of your image-making. It's frighteningly easy to overdo with such powerful camera and software color controls, making an image that appears incredibly unnatural.

Meanwhile, we want color to be consistent across our entire photography process – in other words, it’s great when the colors in your photograph look excellent on the computer screen, and look like the same excellence when you print the photo or submit it to a website. Unfortunately often the photo looks different from camera, to screen, to printer. If this happens to you a lot, then you are probably experiencing a color management problem.

There’s no easy way to solve color management problems. And to solve them, you’ll need some more detailed technical information. And actually technical information regarding color for computers, software, and equipment like monitors and scanners and printers is a time-consuming task at best, and at worst, a total mess. There’s no simple international standard for color management, and there’s many different ways that software programs and hardware devices define and use color, and literally thousands of different products to negotiate. There’s a lot of kinds of math involved to get your software to reproduce and mimic various kinds of color – an immense amount of engineering between taking the digital photo and printing it. Thus a most important rule is this:

                READ YOUR OUTPUT. READ YOUR PRINT. READ YOUR MONITOR.

See what the photo looks like, i.e., ‘Read’ the photo. If you intend to put the image up on a screen, website, or social network, then test the image by putting it on the website (you can always delete it if it looks crummy). It can be a little costly, but it also can really pay off to make a test print with your printer. But don’t just leave it online or on your desk, look at it. First, is it too grainy or sharp enough? Is the exposure correct? Third, are the colors comparable to what you have on your screen on your computer, when you're looking at the picture in your image-processing software?

If it looks the same and looks great, then leave it alone, change no settings, and move on. But if it doesn’t appear the same in your image-processing software and then online, or onscreen versus in print, then you can be sure that some odd color management translations are happening between the Color Space, and the Color Profiles. What you need to do to resolve the problem color changes is called Color Management and Color Calibration.

To get to Color Management you need to know some basic jargon:  

Color SPACE (often called Working Space, or Reference Space) this is generally independent of your equipment.  Color Spaces can be big or small. The bigger they are, the more color definitions they can include, and thus the bigger the range of colors you get to work with. The smaller they are, then the smaller the range of colors you can use. So, if you have a photo set to a big color space with lots of colors, you may encounter problems when a printer or website has to get rid of data and translate it to their smaller color space. Color space today comes in three main types: sRGB, a smaller color space; Adobe RGB, basically a medium-sized color space;  and PhotoPro RGB, quite large. You won’t see the difference between sRGB and PhotoProRGB if you don’t have a computer monitor that can handle the wide range of colors of the PhotoProRGB definitions.

You can check the color space when you have the photo open, you can check the color Mode (in Photoshop it’s under menu Image – Mode). Simply select RGB. When you save a photo with Photoshop, you can also select the color space of the photo. Here’s what this would look like – look for the checkbox marked sRGB:

See the checkbox that says ICC Profile: sRGB? Just make sure it is checked.

You can also change the color space in Photoshop using the Edit --> Color Settings menu. A dialog menu will come up like this:

The color space here should be the same as when you save the file... make sure it says 'preserve embedded profile' for each of the three color management policies too.  [GIMP users... I'm not sure where this kind of control is in GIMP... have you found it? If yes please specify in your comment.]

Feel free to click on the drop-down menus and see what the choices are. For instance under RGB you'll find sRGB, ProPhoto, etc. My advice to you is this: always use sRGB as your main color space. Anything other than sRGB is way out of range for most compact digital cameras today. Also, sRGB’s by far the most common color space used online and in print today. If you want or need a much bigger color space, then go with ProPhoto RGB… if and only if you have access to a ten-thousand dollar printer, specialty inks, an excellent digital SLR camera, and a fancy computer monitor, and archival printer paper. You might get to that level of investment if you work in print media, or work as a professional art photographer. Otherwise, for color management you really only need to make sure your photos and your software are set to sRGB color space.

Now, to make matters more complex...

Color PROFILE (ICC profiles for each piece of equipment that you’re using) Each piece of equipment that you use, such as your camera, your monitor, and your printer, has its own color profile. The Color Profile tells your computer how each piece of equipment can work in or out of the range of colors defined in your Color Space. If you have a monitor, a printer, a camera, and a scanner, you may be dealing with at least four different color profiles that all relate differently to the color space.

Color Management tells your computer how to negotiate all of the color profiles of your equipment within the color space that you’re using. Color CALIBRATION is when you match the settings of your camera or scanner to your monitor and printer, website, or other output. When they all match as closely as possible, then your system is calibrated, and usually your photo looks the same on screen as it does when printed.  

This is a lot more difficult than it seems like it should be… Windows is a bit different than Mac OSX, for how to set the color space of your monitor. Fortunately you can use an automatic device to calibrate and test your monitor. For example, here’s my "XRite EyeOne" color calibrator on my laptop’s computer screen:

It’s basically automatic, and makes sure that your monitor is all in order. It plugs in with a USB cable, and syncs up with it's own software, and then sets the ICC Color Profile. A calibrator like this is really the only way to make sure that what you see on screen is true to what other people using their own calibrated screens would see. Besides EyeOne, other affordable brands are Pantone Huey, and ColorVision Spyder. Both are mouse-sized doodads with a tiny visual sensor in them that responds to the light emitted by your monitor. If you're serious about making sure that graphic designers, publishers, and printers get the colors in your images just right, then it is a wise idea to spend $100 on a decent color calibrator.

Another Pro Tip: If you’re sending your images away for someone else to print – then ask them what color settings you should use to get the most consistent results. A good printer will tell you what settings are best for their printing equipment. Same with a good website that needs photos. Ask them what color space or color profiles they need, and then DO WHAT THEY SAY. Color is a complicated set of balances, and when any printer has a specific series of settings that make pictures look their best, then just follow their directions. Even if you have your images set to sRGB, if they say they need ProPhoto or they send you their own ICC profile, then use their method, not your own personal favorite.