Canon MARK IV User Manual (en)

The color space refers to the range of reproducible colors. With this 
camera, you can set the color space for captured images to sRGB or 
Adobe RGB. For normal shooting, sRGB is recommended.
Select [Color space].
Under the [1] tab, select [Color 
], then press <0>.
Set the desired color space.
Select [sRGB] or [Adobe RGB], then 
press <0>.
This color space is mainly used for commercial printing and other 
industrial uses. This setting is not recommended if you do not know 
about image processing, Adobe RGB, and Design rule for Camera File 
System 2.0 (Exif 2.21). The image will look very subdued in a sRGB 
personal computer environment and with printers not compatible with 
Design rule for Camera File System 2.0 (Exif 2.21). Post-processing of 
the image with software will therefore be required.
 Setting the Color Space
About Adobe RGB
If the captured still photo was shot in the Adobe RGB color space, the 
first character in the file name will be an underscore “_”.
The ICC profile is not appended. See explanations about ICC profile in 
the Software Instruction Manual in the CD-ROM.