RGB differences between Adobe and Affinity

[Petar Petrenko]

I've just noticed something interested. When I create Magenta color (0 100 0 0) in InDesign and Affinity and the convert the color space to RGB, you can see some differences (see the attachment). Both, Adobe and Affinity have the same color settings so I wonder why these differences occur.

[walt.farrell]

I know you said the color settings were the same, but just to be sure: Did the document have the same CMYK color profile and Rendering Intent in both applications before you did the conversion to RGB?

[Petar Petrenko]

Yes, relative colorimetric.

[walt.farrell]

And both were Coated Fogra239?

Perhaps InDesign does not take the source profile into account when converting from CMYK to RGB as (I believe) the Affinity applications do?

You could try having two different documents in InDesign, with two different CMYK color profiles. Setup the same color in both, then convert to RGB, and see if you get different RGB values (as you should) or the same RGB value. You could also try that with the Affinity applications.

[David in Яuislip]

Curious, this is my result

[Petar Petrenko]

4 minutes ago, David in Яuislip said:

Curious, this is my result

You used different color profile. I compared conversion of M100 in InDesign and Publisher with same color settings. Can you reproduce the same result as me?

[David in Яuislip]

I'm going nuts, I'll try with Publisher but I don't have InDesign and only a limited supply of papers in an ancient Photoshop

[Petar Petrenko]

3 minutes ago, David in Яuislip said:

I'm going nuts, I'll try with Publisher but I don't have InDesign and only a limited supply of papers in an ancient Photoshop

OK. Compare Photo and Photoshop with the same settings from my attachment.

[walt.farrell]

Also, please see:

 

[lacerto]

R236 G0 B140 is conversion value of M100 when the CMYK sourceRGB target is the Affinity factory default (US Web Coated v2). When using Coated Fogra 39, Affinity apps, too, produce  R230 G0 B126.

The color profiles specified in the Preferences (working profiles) only determine the initial profiles (the other half of the pair is defined by the user when creating the document); the underlying RGB-CMYK pair can subsequently be changed by the user so the profiles specified in the Preferences do not play any role after such change. 

[Petar Petrenko]

13 minutes ago, lacerto said:

When using Coated Fogra 39, Affinity apps, too, produce  R230 G0 B126.

I got this value in InDesign. In Publisher it is R236 G0 B140.

[David in Яuislip]

I get R230 G0 B126 as well. I'm glad I don't do this for a living