I really, really, do not want to start messing around with my printer profiles, especially since I already know what CMYK color I need in Illustrator.
It may appear to be the same on the screen but when it prints, my printer profile shifts it again so that it is different than what I need. However, if I start with some other values in the color picker and then change the values to RGB 0, 80, 93, when I change the picker to show CMYK values it shows 93.37, 55.88, 49.28, 29.89 which is not what I need. If I immediately change back to CMYK the values are correct, I am guessing that Illustrator does not do any calculations for this if the values are not changed. I enter this into the color picker then change the picker to show RGB which is 0, 80, 93. I have a target CMYK color of 97, 42, 42, 42 which I know matches what I need when it prints. Illustrator RGB working space is set to sRGB IEC61966-2.1, CMYK working space is U.S.
I would like to work in Illustrator in CMYK color space and have a different application that only works in RGB. I have an issue that I have not quite found in the forums yet.