Illustrator alters saved RGB colors to dull CMYK approximations.

[cwcsdc]

Illustrator alters colors saved as RGB to dull CMYK approximations, even for documents with RGB color mode.

Here are two examples:
  • when I double-click on a red swatch that I had saved as R=255, G=0, B=0,

     I get C=-0, M=89.11, Y= 90.01, K=0, or R=205, G=48, B=50, a duller red color;
  • when I enter R=255, G=0, B=0 as the Fill color in the Toolbar:
     • the first time I double-click to re-open the Color Picker, the original values R=255, G=0, B=0 are displayed;
     • but when I close the Color Picker and double-click the Fill color to re-open the Color Picker,

       I get R=205, G=48, B=50 the same dull red as above.

Please enable Illustrator to keep saved RGB colors unchanged, at least for RGB color mode docs.

[Monika Gause]

How is your color management set up?

[Lukas Engqvist]

You are working in CMYK colour mode? You can, just change document colour modet to RGB.
Edit > Document Colour Mode > RGB

Could also be if you have a missmatch between documents RGB and working RGB (one is set to sRGB and the other Adobe RGB?) I have not exepienced problems in RGB documents, so we may need more information on your version of Illustrator and your Operating system.
If you create swatches from the swatches panel do you get the same problem? 
You can save RGB colours in a CMYK colour mode only if they are defined as spot colours.