Colour Profiles

Key Vocabulary to Remember Under and Over Exposure

Introduction

Colour Profiles are a highly important part of the photography workflow. They are a set of conditions that govern the way in which a particular device interprets colour. Any device we use to capture or show an image, including our eyes have specific characteristics that influence how an image is perceived. During our technological evolution and based on limitations of displays, cameras and printing technology, common rules to describe colour have been designed. Many decades have passed and results may still not be entirely consistent. However, we should be aware of areas where we can consistently reach good results.

Inconsistent results

Unfortunately, colour profiles are frequently omitted from discussion due to the fact that acceptable results are frequently achieved, on the one side, and due to the fact that colour profiles are, unfortunately, still rarely consistent on platforms. As there are few possibilities of accurately simulating how a photograph looks on the intended publishing medium, most of the work is centered on compensating for various noticed limitation in the edited image. This is time consuming and an non-ideal approach that is best avoided.

Current PC configurations as well as most programs can and do respect colour profiles. Unfortunately, colour consistency, or the ability to show predictably the same intensity and saturation is not a common concern for software development. The operating system, whether we consider Linux, Windows or MacOS, tries to create and include a centralized way to manage the output on the screen through its control panel settings. However, there are limitations on how the colour profile is imposed on the way in which images are displayed and this occurs particularly if the graphics applications use non-standardized ways of displaying images due to performance or ability goals.

Note that even if all guidelines are followed strictly, there may still be many situations where colour is not accurately processed. The suggestions presented in the document refer to best practices that vastly improve predictability.

Types of Colour Profiles

Display

The most likely colour profile to encounter is for displays. As the final element to showcase an image and the reference on most, the display is essential on all scenarios. Unfortunately, due to different technologies and variation in product lineups, few displays from different manufacturers are highly comparable, yet many more will be present and used to evaluate the quality of photo creations. This is the main reason why content creators frequently choose to exaggerate their creations, particularly in colour and contrast, so that they will be able to show reasonably well on different display.

Display colour profiles are used to define how each point in the image is to be represented on the screen and represents a computation that is applied based on the initial information supplied, such as your photo's content. Even in the absence of a colour profile, there is an implicit translation that is applied, ending with reasonable output in all circumstances. Of course, absent any particular support from the display manufacturer, this is the most likely result. However, most manufacturers ensure that computers, as they are used for editing images, are supplied with improved abilities to maintain consistency. This is the reason that displays are supplied with colour profiles which are by default installed and activated on computers nowadays, no matter if you use Windows, MacOS or even some Linux distributions.

sRGB The most common colour profile and the one you should aim for in most situations is the sRGB one. Standardized in 1999, it is the format to which all manufacturers of displays and software cater to. Basically everything that is published on the internet is aimed at this standard. Although it is slightly older, the colour profile is reasonably expected to be reached and even superseeded by most manufacturers, creating a common platform expectation that should be targeted by any graphical creation.

It is true that the colour profile was designed when Cathode Ray Tubes where the standard display technology of the time, but it is well suited even for modern ones such as OLEDs, as well as the popular LCD ones. In many ways, it is true that such a colour profile may not accurately represent the abilities of your or your viewer's particular display. However, the fact that it is consistently available and applied, leads to predictable results and this is the main concerns when you aim for high quality photography.

An important fact to remember is that any colour profile presented below is larger or wider than sRGB, but fewer displays may be certified to reach such a good performance. Nowadays, some display manufacturers may not mention that they certify their products for the sRGB profile, but they are certainly respecting established guidelines. This is the main reason why, despite all technological advances, sRGB is still relevant or the basic standard that you should always aim for, unless specific requirements are imposed.

Adobe RGB and other standards

Adobe, a well-known American company, has been highly active in promoting their own standards that attempted to reach consistency in software they were promoting and to achieve high market penetrations. Unless specifically directed to use such a profile, you should use the sRGB one to achieve results that are easily predictable on most displays and software.

DCI-P3

This very high specification is reserved for very high quality displays. Due to current technology abilities, the only highly-available mass market product to incorporate it is OLED screen, with few LCD displays also available to reach these high specifications. Note that such a colour profile does not translate in any special ability to edit or see the images in a revolutionary way, it just means that the display could potentially display images requiring such colour profiles with good accuracy. As very few images and software actually require such capabilities, the DCI-P3 certification is important mostly to ensure that images can be always shown with accurate colours when required for less demanding editing, such as the ones that cater to sRGB and lower demand colour profiles.

Note that a DCI-P3 display may be present in a laptop, on a tablet or any device that may not be configured right away to display accurate colour. The end user is expected to be more attracted due to extremely vivid or over-saturated colours than an accurate representation of them. You may have to make extensive modification to disable or adjust saturation and contrast enhancements in the software that accompanies your computer, in graphical settings, to reach accurate results. You may also need to watch reference images and adjust these settings manually if you do not have colour calibration equipment available.

The above mention is extremely important as you do not have an out of box, simplified experience of accurate colour display even if you invested in costly or high specification equipment. You still need to adjust it to more accurately represent its capabilities. Keep in mind that this is the only way to achieve very good results and what matters is that you have a product that can reach the desired specifications instead of a cheaper one that will never be able to and offer more frustration when expected to behave accurately.

Colour profile use

In windows

It is essential to use a specific colour profile not only in windows but also in Windows applications, and, unfortunately, there are some applications that can

In MacOS

In Applications

Graphics and Image Editors

Krita

In many ways, Krita is an extremely popular image editor, the best open-source software for creative photo editing. It is much easier to use than GIMP, free compared with the traditional software for Image Editing, and it is available both for Windows and Linux. While not offering the same capabilities and extensions or plugins as Adobe Photoshop, the most versatile image editor, Krita fares favourably well for more experienced users, while it may be somewhat more difficult to work with for first users. However, ease of use depends on features and Krita frequently makes learning about such capabilities worthwhile. It is also possible to use Krita for basic image editing as well.

GIMP

GIMP was, until recently, the only open-source software that may come close enough to the capabilities of Adobe Photoshop, before Krita evolved. The software was first developed for Linux and later expanded to also cover Windows. While powerful in itself, GIMP does not adhere to the standard menu-driven operation as other programs, making it slightly more difficult to use than well-known image editors such as Adobe Photoshop. Due to its long presence on the market, there is a very large variety of tutorials that are help to get you accustomed to GIMP.

Adobe Photoshop

Adobe Photoshop is the golden or most popular image editor software. While it is a commercial application and is relatively expensive, counting at more than 200 Euros or USD per year for a single license, Photoshop is the widest use software for image editors. It is much more powerful than what most individuals need, being useful particularly for advanced users or the ones that require specific functionality, features, effects or the ones that require particular plugins to work with. As a rule of thumb, you may not need such a software application, although understanding the logic and operation of Adobe Photoshop creates expectations and improve your chances of adapting to concepts used in just about any image editor.

One of the features that is applied thoroughly in Adobe Photoshop, regardless of the operating system, is the ability to simulate particular colour profiles, on the fly. Such a feature is useful to determine how certain images may end up looking when printed. For instance, in the typical CMYK colour gamut of a printer, the image may look totally different from the perfectly fine and vivid in sRGB, as the colour profile used by all displays.

Web browser

We may not be aware that most web browsers do not respect the same colour profiles as expected, by default, showing any image with slightly more muted colours than it may be expected. This is a common occurence, caused due the insufficient interest in developing consistently the application support for colour profiles and enforcing them by default.

All common web browsers, Google Chrome, Mozilla Firefox, Microsoft Edge, can include and use the colour profile specified in Windows. Mozilla Firefox is closer to the ideal out-of-box experience required for colour profiles by default, while Chrome and Edge can have the same capability, but it is not active by default, for unknown reasons.

The required settings can be carefully applied in each application, following the guidelines below. Special care is required to modify only the required parameters.

Mozilla Firefox

Type in the address bar about:config, then, after agreeing to the prompt regarding the risk of modifying settings, enter in the search bar that appears in the page section, the following keyword, gfx.color_management

Note that there are two settings that have to be flipped from the "false" value to "true", by clicking the double arrow button in the right side of the row, for the following parameters, gfx.color_management.force_srgb and gfx.color_management.native_srgb. A succesful modification changes the parameter name to be written in bold. There is no need to save the settings, they are immediately applied. You can close the tab and the settings will be always applied.

Google Chrome

Type in the address bar chrome://flags/, then, after agreeing to the prompt regarding the risk of modifying settings, enter in the search bar that appears in the page section, the following flag, Force color profile

Note that there are two settings that have to be flipped from the "default" value to "sRGB", by selecting the value in right side of the row.

Microsoft Edge

Type in the address bar chrome://flags/, then, after agreeing to the prompt regarding the risk of modifying settings, enter in the search bar that appears in the page section, the following flag, Force color profile

Note that there are two settings that have to be flipped from the "default" value to "sRGB", by selecting the value in right side of the row.