CMYK to RGB

Basic color management,  CMYK is a smaller gamut than RGB.

David,

Thanks for your reply.

However - what we don't understand here is that we have been using previous versions of Corel 2007 for graphics etc in our designs and we don't understand now with the new version of Corel 2021 why when the CMYK to RGB ends up in complete different colours to the original artwork

Joe

There is no version 2007, do you mean X7?

If so the default color management settings are identical so if there is a change in color between the versions you've done something in you color management settings in one or both versions.

Please attach screen captures of your X7 and 2021 color management settings. 

Short answer: RGB has 16.8 million colors, CMYK uses only about 64,000. That explains why you will lose some colors, especially bright colors. By the way, depending on the color profile, this loss may be greater or less, it may even go unnoticed. For example, using "Perceptual" rendering you will notice that the change is less abrupt.

The message you get explains what may be wrong and suggests how to correct it.

In the Print dialog, Color tab, choose if you want Draw or your printer to handle the conversion, from the "Color conversions" dropdown menu.
There are a couple of other settings in that tab that also will affect the printed result.