Photoshop CC is a complex piece of software. Most of us barely scratch its surface in terms of the features we use. Thankfully, it doesn’t matter if we’re not familiar with every aspect of this vast program if only we achieve the results we want. One of the hurdles in Photoshop has always been understanding how it handles color and what effect different color settings have. This can be mind-boggling for new photographers and even catches a few seasoned ones out.
There are 6 color settings to consider in Photoshop
#1 – RGB Working Spaces
Some basics
Under “Color Settings” in Photoshop, the first item needing attention is choice of RGB working space. What is this? It’s your editing color set, if you like, where all the various tones of red, green and blue are split into values between 0 and 255 and blended to make 16.7 million possible colors. We can’t separate all these colors with our eyes, but mathematically they’re there.
This simple RGB color wheel shows the relationship between primary (red, green, blue) and secondary (cyan, magenta, yellow) colors. For example, a fully saturated magenta tone contains no green (RGB 255,0,255), so sits opposite green on the wheel. Tertiary colors are created by blending adjacent primary and secondary colors.
All RGB working spaces have the same number of colors; the gamut they cover is the main difference between them. Choice of RGB working space is, therefore, mainly about picking a gamut that suits your needs best.
Standard RGB working spaces (e.g. sRGB, Adobe RGB or ProPhoto RGB) are used for editing because they are “well behaved”. In other words, we know what to expect from them when we edit our photos. To illustrate this, if all three red, green and blue (RGB) values are equal in any pixel, the tone will always be neutral, be it gray, black or white. Any adjustments made to shadows, mid-tones or highlights cause the same degree of change, too, so editing is always predictable.
Choosing an RGB Working Space
Here are the three main choices of RGB working space:
sRGB
sRGB might be a good choice of working space if all you ever do is publish photos on the Internet and get your prints done at the shopping mall (i.e. a commercial photo lab). It’s one way of keeping things simple, but does potentially forfeit a lot of color data between camera and Photoshop, especially if you shoot RAW.
Some subjects are better suited to this color space than others, like portraits. Skin tones are likely to be encompassed by the sRGB color space, so you don’t lose data by editing in it. The types of subjects you shoot may play a part in choosing a working space.
The popular assertion that this color space is the “Internet standard” is partly true, though slightly outmoded. Most people can’t see much color outside of sRGB because of the standard gamut of their monitors, so a bigger space would be largely wasted on your web audience.
Adobe RGB
Adobe RGB is recommended to anyone who does their printing at home or who supplies third parties with images for publishing. Even humble models of inkjet printer produce colors outside of the sRGB gamut, while only high-end printers exceed Adobe RGB in output.
The Adobe RGB color space was designed to encompass the output of CMYK printers. It is often seen as a good all-rounder for the average photographer, and you can easily convert files to sRGB for the web at the end of editing if desired.
Landscapes benefit particularly from Adobe RGB, largely because of the cyan and green colors lost when converting down to sRGB. To a lesser extent, yellows and oranges are also truncated.
Since most browsers are now color-managed by default, you can get away with saving photos in the larger Adobe RGB color space for the web. You must embed the profile into the image file if you do this, otherwise, your photos will look desaturated to most people. Only a minority of your audience will benefit from the bigger color space, alas, but it could be worth trying among a group of keen photographers with wide-gamut monitors.
ProPhoto RGB
ProPhoto RGB is the largest of the three commonly used RGB working spaces, and it’s the one that best preserves all color data between a RAW file and Photoshop. A purist would ask; why would you want to throw color away needlessly? You don’t always discard color with a smaller color space, of course, depending on the content of your photo.
ProPhoto RGB is a good choice if you use a high-end inkjet printer capable of colors outside the Adobe RGB gamut, but there are caveats attached to its use:
- Because ProPhoto is spread over such a wide gamut, you’re forced to work with larger 16-bit files to avoid posterization, or banding. (The opposite is true of a small working space like sRGB, which is ideally suited to 8-bit editing.)
- Since ProPhoto RGB produces colors beyond the capabilities of any monitor or that of human vision, you’ll be working partially “blind” when you edit in this color space. This is a trade-off that many accept in return for extracting as much color as possible from their printer.
Note: some photographic subjects, particularly those with a deep yellow color, lose detail straight away merely by opening them in Photoshop in a smaller color space (i.e. sRGB or Adobe RGB). It’s possible to see blotchy, posterized areas in photos of yellow flowers, for instance, in anything less than ProPhoto RGB, and the effect is worse the smaller a working space you select. This makes it desirable to print such subjects directly from ProPhoto RGB.
Again, there’s nothing to stop you from editing your files in ProPhoto RGB and then converting down to smaller RGB color spaces when required. Remember; you can’t convert up to a bigger color space and get data back.
ProPhoto RGB is not typically an in-camera option. You need a RAW > 16-bit workflow to make it a useful choice in Photoshop.
A comparison of RGB color spaces. Note how the profile of an Epson 2200 printer with matt paper exceeds the Adobe RGB gamut.
#2 – Monitor RGB (check your monitor profile)
Also under the RGB working space menu you’ll see the “Monitor RGB” heading. This is not a profile you’ll want to use as a working space, because it effectively turns off color management in Photoshop. One thing the Monitor RGB selection is useful for is checking that Photoshop is accessing the correct monitor profile. The profile in current use is listed beside “Monitor RGB”.
If you’ve created a custom monitor profile and notice that color is wayward in Photoshop, one thing you can do is temporarily switch the monitor profile back to sRGB in your OS settings (Adobe RGB for wide-gamut monitors). If this improves the color, your own custom profile is probably corrupt and you’ll need to delete it and create another. Again, the “Monitor RGB” working space option will verify the profile in use.
#3 – Color Management Policies
Under “Color Management Policies” in Color Settings, select “Preserve Embedded Profiles” in all three drop-down menus.
There is a case for unchecking the 2 boxes next to “Profile Mismatches”, since you’re unlikely to act on the alerts they produce. The first box “Ask When Opening” might be useful if you want to be kept in the loop and know immediately if a file has a different profile embedded to the one you edit with. You can disregard the second box “Ask When Pasting”.
It’s desirable to check the box next to “Missing Profiles”. When opening an image file without a profile embedded, you can sometimes guess the correct color space based on where it came from and then assign that profile to the image. You may also choose to open the file without a profile and then assign different profiles in Photoshop to see which looks best.
#4 – Assign Profile
The vital thing to learn about “Assign Profile” in Photoshop is that you should leave it alone in most situations. Many people don’t distinguish between this and “Convert to Profile”, which is a mistake.
A color shift occurs when wrongly using “Assign Profile” to convert files from one known RGB color space to another. “Convert to Profile” uses a relative colorimetric rendering intent to match destination colors to source colors as closely as possible.
Assign Profile applies the RGB values embedded in a photo to a different color space without any attempt to match color. This often causes a huge color shift. You’d only use this feature on a file that had no profile embedded or that had one assigned upon opening that you’d like to change.
#5 – Convert to Profile
If you need to convert a file from one RGB color space to another in Photoshop, “Convert to Profile” is the right tool for the job. A relative colorimetric rendering intent is used to match color between different color spaces. If you’re converting from Adobe RGB to sRGB, for instance, colors outside the sRGB gamut are matched to their nearest in-gamut equivalent.
Convert to Profile is typically used to convert between RGB color spaces, since most of us have no need to convert to printer or CMYK profiles within Photoshop. When converting between RGB files, “relative colorimetric” is always the rendering intent used, even though it’s possible to select other intents from the menu.
#6 – Proof Colors
You wouldn’t ordinarily check “Proof Colors” under the “View” menu unless previewing the color output of a printer or other device. The colors it displays are based on the selection made in the “Proof Setup” menu. Some people assume they should use Monitor RGB proof colors for editing, but, as we’ve already noted, this turns off color management in Photoshop.
Proof colors being used to simulate “Color Blindness – Protanopia-type”. More typically, you’d use this function to preview and edit print colors so they matched the original RGB screen image satisfactorily (a technique known as “soft-proofing”).
The normal method for using “Proof Colors” is to open a duplicate image next to the original, apply the printer profile to the duplicate using proof colors and then edit so it closely matches the original. This is basic soft-proofing method, though a full description merits another article.
Checklist
- RGB Working Space: Choose Adobe RGB if in doubt. It’ll encompass the output of most monitors and inkjet printers.
- RGB Working Space: Take note of the Monitor RGB selection to ensure Photoshop is using the right monitor profile.
- Color Management Policies: Select “Preserve Embedded Profiles” in the three drop-down menus and check the “Ask When Opening” box next to “Missing Profiles”.
- Don’t use “Assign Profile” to convert from one RGB space to another. It causes unwanted color shifts. Use it only when the original profile is unknown, which shouldn’t be often.
- Use “Convert to Profile” to convert from one known RGB space to another. This matches color as closely as possible between the source and destination color space.
- Proof Colors are used for previewing the color output of other programs or devices, or to see how an image will look to a color-blind viewer. For normal editing, this should be turned off.
Conclusion
I hope that clears up any confusion you have had around color settings in Photoshop. Please post any comments and questions below and I’ll try to answer them.
