cmyk-values within rgb-document

[Gmit]

First i asked that question that question on facebook and it failed. Many didn´t understand that question correctly and told me about the basics about color-management and how that is a bad idea,......
that´s not the question.

If i let´s say have a AdobeRGB Document and choose a color with the cmyk-sliders. They are clearly limited and don´t cover the whole AdobeRGB colorspace. The question is to what colorspace are they limited?
I changed the default cmyk-colorprofile in the preferences but that didn´t affect the cmyk-sliders in rgb documents in any way, so it doesn´t seem to be based on that.
So what are the cmyk-sliders based on?

 

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[Gmit]

yeah it´s not the question "should i work this way?" No, obviously not^^
I asked out of curiosity "what is happening under the hood?".

Yeah the "lock colorspace" also wasn´t clear to me, for a longer time.

At least on my test it didn´t take into account the last cmyk colorprofile i used or the default cmyk in the preferences.
So let´s say i am confused.^^
I changed my default cmyk profile to "Japan Color 2002 Newspaper" which is very small and the K100 also ends up in this brown-dark grey.
And did create some documents in that colorspace and saved them and stuff. Still when i created a new rgb document and created a K100 Color which was way darker and the brown-tint is gone.
I created a ROMM RGB Document and put a bitmap with the newspaper profile in it. That colorspace is way smaller than i could create with the cmyk-sliders.

At first i thought they simply convert the values like these online color-converter: https://www.rapidtables.com/convert/color/cmyk-to-rgb.html
(which yeah are quite funny, but are waaay too simplified) But a simple tested proofed me wrong.

So i am at a loss. Krita for example asks for an colorprofile when changing the colortool to a different colormodel than the document colormodel.
That´s what i get, but i don´t get what is automagically happening here.

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[Gmit]

Maybe my computer needed an additional restart or so, to take on the new cmyk-profile. I did a quick retest and now it behaved exactly as you just described.

So, i would leave it at that, i already put so much time in that question and asking different people, checking what different apps are behaving,.... and all of that just out of curiosity.
Your explanation makes sense, and from the quick test it looks like that´s how it should behave. Unless someone proofs a different behavior.
I can´t say that this knowledge helped me work better, i don´t put cmyk-values in my rgb-document^^ But it made me more confident in my knowledge of the Affinity Apps, i know more what is happening under the hood.

And i choose that Newspaper profile to have a easy time to tell the different cmyk-profiles apart. Interesting you say that "if often a bit overdone" for that brownish tint. But i also to 99,99% of the time don´t work with newspaper-paper or similar, but good to know

Thank your for your time and input, most likely the best source of information in researching that question.

 

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