In the book, a lot of time was spent talking about Photoshop. There’s a reason for that: Adobe has been concerned with color management from the very beginning. Remember when I talked above about scanning film and printing the results on paper with ink? Photoshop and other desktop publishing apps needed to manage color as soon as that first pixel came off the scanner on its way to the printer.
But we all have a lot of tools that we use to assemble websites and native apps. How do they manage color?
We can’t cover all tools that are in the market, so we’ll focus on a few of the most popular apps and how they perform common tasks.
It's also likely that our tools will evolve over the coming years as color management becomes more important while building apps. This page can be updated much more easily than a book!
Much of our work begins with vectors. Whether it’s a simple wireframe or a complex illustration, many visual elements start as shapes in an editor. As you’re creating these objects, it’s a good idea to think about color management early in the process.
Adobe uses the same color management engine throughout all its products, and Illustrator provides nearly identical color settings as Photoshop:
What’s more, Adobe lets you synchronize your settings across the entire Creative Suite. Using the Bridge app, it's easy to make sure that your vectors and bitmaps handle color consistently.
Sketch is another popular app for drawing vectors and saving bitmaps. Internally, the app stores raw RGB color values and renders them to the display using your monitor’s color profile. Bitmap image layers are drawn using any embedded profile in the source image (although that information won’t be included in the output file). If you're working on an iMac with the wider Display P3 gamut, these two issues can lead to color shifts between what you see on screen and your final output.
When exporting bitmap graphics, Sketch attaches an sRGB profile to the output image by default. The app also has a Save for Web option that removes EXIF metadata and the color profile information:
If you’re exporting SVG graphics, no color profile information is embedded since support for that feature isn’t supported well in browsers.
Photoshop isn’t the only image editor in town. Many folks prefer to use other tools instead of, or in addition to, this well known manipulator of pixels. Let’s take a quick look at how a couple of popular alternatives work.
When you open an image with Pixelmator, it uses any color profile that’s embedded. The app also takes a very pragmatic approach for new documents or ones without a profile: it uses sRGB by default in setting called “Universal”.
You can also modify the color profile of a Pixelmator document using the Image > Color Profile… menu item. It even uses the same keyboard shortcut as Photoshop: ⇧⌘K.
By default, the app will do a “Match to Profile” which behaves exactly like Photoshop’s convert functions: pixels are modified when a new profile is selected. You can use the sheet’s gear icon to choose the “Assign Profile” mode where no raw color values are changed:
When you Export a document, the current color profile is embedded in the output image. The Web Export feature can be used to save a file without an embedded profile. If you’re exporting slices, no color profiles are saved.
Acorn’s defaults are also familiar—the tool respects embedded profiles, and uses sRGB for images without profiles and new documents.
The app lets you choose a “Document color space” with the Image > Color Profile… menu. After choosing a color profile from the popup menu, you have an option to "Assign to pixels" or "Match and modify pixels". The default is to assign where no raw pixel values get modified. If you need to convert the pixels from one color space to another, use the match option. The “Pixel processing profile” setting in the sheet can be ignored since it’s only used to optimize image processing.
When you export a document with Acorn, the current color profile is embedded in the output image. The Web Export feature has a checkbox that lets you control whether a profile is embedded in the output image.
Color is important on the web, as you first saw with Dr. Eyeful’s site. Many of the tools we use to craft our pages have color management built into their editing and previewing functions.
Typically, these tools use the same underlying technologies as our browsers, so we’ll only summarize the behavior here. The book's chapter on how web pages are color managed is much more comprehensive. For now, just take note of which rendering engine is being used by your favorite tool.
It’s also worth noting that most tools on the Mac will use WebKit to render content (Apple supplies tools for developers that make it easy to include these capabilities.) When in doubt, it’s usually safe to assume that your tool will display HTML and CSS like Safari.
Macaw is a visual web design tool for creating semantic HTML and CSS. Since you’ll be using it to write and preview content that will be color managed, it’s important to know how it handles profiles.
When editing or publishing, colors specified in CSS are rendered as raw values using the display’s color profile. Images are rendered using any embedded profile, otherwise the display’s profile is used.
This is exactly how Google Chrome handles color. It’s no surprise then that the Blink rendering engine is being used behind the scenes in this app.
Coda is an integrated development environment (IDE) for creating web sites. While many of its features revolve around a powerful text editor for HTML and CSS, it also has excellent previewing capabilities for the pages you’re creating.
These previews are generated with WebKit; the rendering engine that’s used in Safari. CSS is rendered in the sRGB color space. Images without an embedded color information are displayed using the sRGB profile, otherwise the attached profile is used.