I wouldn't expect Walmart, or any store, lighting to be that great either. It might actually be bringing out the blue.
BTW, not all of us have a nice big window where we can stand, and for me that would be half naked, to apply our makeup, So, maybe ask your expert what we should be doing in that case.
I've never had much luck with trying to find natural lighiting. Either the sun is shining directly in the window, in which case you're either squinting or only lit on one side. I've tried getting pictures outside, but I have a shady back yard.