Problems changing from RGB to CMYK in Illustrator

[defaultd7w81ejmq6m7]

Hello,

I wonder what I am doing wrong: I tried to convert from RGB to CMYK but the color changes drastically. You can see the difference between the attachements. The lighter blue is RGB and .psd. The 2nd one I changed to CMYK in Illustrator. 

Many thanks already in advance!

[Ton Frederiks]

Are your Color Settings the same in both Illustrator and Photoshop?

How did you change from RGB to CMYK?

[Doug A Roberts]

Are you expecting it to not change?

The lighter blue may be out of gamut for CMYK.

[defaultd7w81ejmq6m7]

Looks like I did it in the wrong way, sorry guys. Attahed how I did it. I just have to find a right way to make it. Though, I think I should still consider both your answers in the future.

[Ton Frederiks]

If you want to convert an image from RGB to CMYK, do it in Photoshop.

And Photoshop is also the best app for making image adjustments.

If you convert an Illustrator document from RGB to CMYK by changing color mode, your color swatches get converted too and black is not black anymore.

Convert in Photoshop and place in a new CMYK document is the best option.

[Test Screen Name]

I think it's fair to say that "adjust colours" is certainly the wrong way to do it. Changing to CMYK should be a matter of

- ensuring your display is calibrated and showing correct colours

- picking the right CMYK profile for the conversion

- making sure the right RGB profile is assigned

- changing to CMYK

Some colours may change if they are out of gamut, as has been said.

If your process involved any manual adjustment, it is certainly wrong, even if it looks right on screen.

[c.pfaffenbichler]

You write of »RGB« and »CMYK« but never seem to mention the actual Color Spaces. 

What are they?