Set the color to white, but not drawing white.

[Summoner99]

This is bound to be a really simple problem. 
I downloaded an image. I needed to replace some things with white Problem is, when I open the color menu to select the color white, it doesn't actually draw the color white.
https://imgur.com/NN5R1gs
Here we see what the color menu option looks like, and the color it drew onto my image.
Thanks for your time.