Hello, Did you try to zoom both images at 100%? I'm wondering if it is not the shadowing of the paint that makes the image darken when resampling occurs because you are viewing the image at 18.6%.
I appreciate your helping but the zoom thing has nothing to do with this .. it's kinda wierd
Hm, I wonder if it could be a color-management issue... Have you tried changing your Advanced GPU settings to Basic (then closing and restarting Photoshop)?
It might be that you could benefit from updating your operating system if it's not already right up to date.