Color Models and Profiles
Digital images contain a color model and color profile associated with the image file. This is necessary to ensure that the colors in the image are the same when the image is opened and viewed on different devices. For typical image editing needs, Acorn will take care of color management in the background for you.
What is a color model, color profile, and color space?
A color model is a system that converts numbers into colors. Two common color models are RGB and CMYK. Acorn supports editing in the RGB color model (but can open and export CMYK images). RGB uses the three primary colors plus alpha (also known as transparency) usually represented together as (red, green, blue, alpha). These values can be mixed to make all other colors. For example, white with no transparency is expressed as (100% red, 100% green, 100% blue, 100% alpha) and black as (0% red, 0% green, 0% blue, 100% alpha) in RGB. Magenta would be (100% red, 25% green, 100% blue, 100% alpha).
When working in an image editor such as Acorn, the color profile is the range (or gamut) of colors within the color model that you can work in. The color profile ensures that your image is edited within consistent color parameters. Examples of color profiles include Display P3, Adobe RGB, sRGB, and ProPhoto RGB.
You can change the color profile of your image by using the Image ▸ Color Profile menu, and a sheet will appear with the option to modify the document profile, as well as the ability to import or export color profiles. New images created in Acorn by default have the sRGB color profile assigned. This default can be changed under Acorn ▸ Preferences ▸ Fussy Stuff.
Color space is a term which can almost always be used interchangeably with color profile. Color Spaces are a more theoretical term, where profiles represent a serialized version of a color space, for example a file on disk. You assign or change profiles to an image to change its colorspace.
Opening, Saving, & Exporting
When Acorn opens an image without a color profile, or opens an image with a color model that isn’t RGB, the image will be converted to RGB.
If you wish to have your image saved in the CMYK color model for specific printers, go to File ▸ Export ▸ Export and choose the JPEG, JPEG 2000, or TIFF formats. A checkbox option for CMYK will be present in the drop down window.
To export without color profile information, use the File ▸ Export ▸ Web Export menu and check the ‘remove metadata’ box.
To view which colors are outside the range of sRGB when working on a wide gamut display, go to File ▸ Export ▸ Web Export and check ‘Match to sRGB’. This option requires OS 10.12+.