: I select colour #0033ff and get colour #3d58a7 in a CMYK Photoshop file. What could be happening? I am working on this CMYK file and until today all colours could be selected and everything

@Kristi927

To put it simply, #0033ff is outside of the range of colours CMYK is able to represent. Because of this, Photoshop can't store that colour in your image which uses a CMYK colour space.

It has therefore substituted it with a suitable alternative approximate colour prior to applying it to your CMYK document.


If you need to preserve the colour #0033ff in the document, the document would need to be RGB. Specifically, HTML/CSS colours are represented in the sRGB colour space, so sRGB would be able to reproduce all colours that could be specified as HTML/CSS hex colours.
If you need to store the document as CMYK, understand that the limited gamut of CMYK, particularly in deeply saturated reds and blues, means you won't be able to store precisely this colour in it.


Here is a comparison of an RGB and CMYK colour gamut - that is, the range of colours each can represent:



Notice how there are some deep red, deep green and deep blue colours that cannot be represented in the CMYK gamut. But on the other hand, the CMYK does extend further into some other areas like yellow/orange and cyan/blue-green, that RGB doesn't extend to.

Note: The image is only a rough approximation. Also, because you're viewing this on an RGB display, you cannot actually see any colours outside the RGB gamut, so realise that the colours in that diagram aren't intended as accurate.

Vote Up Vote Down

@Deb5748823

When you created your document you were working in the RGB color space, primarily used for digital display of files.



Somehow you converted your color space to CMYK which has a lower range in its color gamut and is used for primarily for print documents



This converted your rgb colors to CMYK. Since the saturation can't be duplicated in a CMYK profile, it was automatically converted.



For a larger discussion between the difference between CMYK and RGB, see this question:

What is the difference between CMYK and RGB? Are there other color spaces I should know?

Vote Up Vote Down