Corel Draw Graphics Suite X5 Shows a Default Color palette in CMYK color mode which has a palette of colors that are not as bright and powerful as an RGB color palette would. The reason being that the colors are made to better replicate how print jobs will appear on paper.
If you wish to see the color display in RGB you can do either of the following:
1. Open up the Window menu - Color Palettes - RGB palette
2. Tools menu - Color Management - Default Settings - change the default preset to "Simulate Color Management Off."