Setting up Photoshop for Web and iPhone Development
Most people who have designed websites or apps in Photoshop will, at one point or another, have had issues trying to match colors in images to colors generated by HTML, CSS or code. This article aims to solve those problems once and for all
Color Management to Match Colors Across Multiple Devices
In the print world, color management typically involves calibrating your entire workflow, from scanner or digital camera to computer display to hard proofs to the final press output. This can be quite a tall order, especially when the devices use different color spaces matching RGB and CMYK devices is notoriously hard.
When designing or editing for TV, calibrating the main editing display and using a broadcast monitor are common; these show real-time proof of how the image will look on a typical TV in a viewer’s home. In such a scenario, color management offers many benefits and is highly recommended.
When designing websites or app interfaces, we want to perfectly match the colors that are displayed on the screen in Photoshop and that are saved in files with what’s displayed in other applications, including Firefox, Safari and the iPhone Simulator. Not only do we want the colors to look the same, but we want the actual values saved in the files to perfectly match the colors we have defined in Photoshop. Colors should not shift or appear to shift in any way, under any circumstance.
Why is this so difficult?
Photoshop applies its color management to images displayed within its windows and to the files it saves. This is a bad thing if you’re working exclusively with RGB images for Web or on-screen user interfaces. With the default Photoshop settings, #FF0000 will actually display as #FB0018, and #BB95FF will display as #BA98FD. The differences are subtle but definitely there.
How Does Photoshop Differ from OS X and Windows?
OS X’s color management is applied to the entire display at the very end of the processing chain, after the main buffer in the video ram. This means that although color management is applied, the software utilities that measure color on-screen (like /Utilities/DigitalColor Meter) will report the same values that you have saved in the file or entered as your code. I believe the color management in Windows Vista and Windows 7 (Windows Color System) works in a similar fashion.
Disabling Photoshop’s RGB Color Management
Each Photoshop document contains a color profile that’s separate from the actual color data stored for each pixel. Assign Profile simply changes the profile in the document, without affecting any of the color data. It’s a non-destructive action: you can assign a new color profile to your documents as often as you like without doing any damage. Assigning a new profile may change the way your document appears on screen, but the data contained in the file will remain unaltered.