General question

hatstead's article explains why you are seeing what you are seeing. 

If the white balance of your camera was improperly set, probably the best/easiest way to fix it is to open the file in camera raw.  You don't have to have a raw file.  The File>Open in Camera Raw command allows you to edit a jpg or tif file in the camera raw editor.  Here, I have 3 screenshots of a jpg file adjusted for different white balance settings.  In the third, after finding the best white balance setting, I have used the eye-dropper tool to click on the white part of the dress to get as close to white as possible.

Of course, other factors such as the calibration of your monitor and ambient lighting in your room also affect what you are seeing.  Many books have been written on this complex subject.

Can you set the white balance on the camera?  

White Balance Explained: How To Get Accurate Colors In Your Photos (photographypro.com)

Wish I could help you, I was just about to go on line with support and ask them the same question, if I try to do something white, it comes out a real light blue or light grey, I never get a good pure white look.  If someone can tell us,why I sure sould like to know also!!