The problem occurred after Windows automatically updated.
My Corel page turned pale yellow along with White on CMYK colour palette also showing pale yellow.
I followed one YouTube help...
Went to Default Colour Management Settings - Colour Conversion Settings - Colour Change - and made it 'None' - pressed OK
The result was - Pale yellow changed to white but at the same time - CMYK colour palette started showing bright colours like that of RGB colour palette.
How to change it to original CMYK colour palette. I checked Windows colour palette - it shows CMYK palette only but colours are not matching.
look here https://community.coreldraw.com/talk/coreldraw_graphics_suite_x5/f/coreldraw-x5/19513/white-shows-a-yellow-hue/85223#85223
your problem is the now default display profile in windows.