Praise the Sun!

@Erosthanatos
 
@Goddess Erosia
 
@Darkest Lunar Flower
 
I honestly think either skin tone shade could work with the Princesses, both seem like natural choices to me. Plus I mean, if the art looks good, the art looks good regardless of skin color.

@zerowinger66  
I did that! :3  

 
That aside I make my Luna dark because I know first hand no matter how much I avoid the sun it won’t get rid of my tan.  
I also know that no matter how white someone is there is only so much melanin one can produce before they either get skin cancer or burned or that ugly tanning machine tan (the kind of a heavy user).  
I also give Luna that tanned skin just to parallel with me. XD

@zerowinger66  
Yeah that’s the weird thing, I can easily picture a human Celestia as a darker or at least tanned skinned woman but I can’t help but envision Luna as a pale white girl.
 
I’m really not sure what makes me feel that because Luna’s pony form actually is pretty dark toned…. Apparently I’m not the only one who feels that way though.

@zerowinger66  
I prefer olive-skinned Celestia and albino-skinned Luna to reflect the effects of constant exposure to their respective celestial bodies like you mentioned.

@Goddess Erosia  
I think a lot of people just try to get their humanizations to match the pony coat coloring - which is why you’ll also see a number of dark skinned Princess Luna and Maud Pie humanizations. Plus, I think the particular shade of purple that’s in Twilight’s mane contrasts nicely on dark skin in the way the shade or purple in, say, Rarity’s, does not.
 
For the royals, I’ve seen artist’s mainly go one of two ways - make Celestia light skinned and Luna dark skinned to match up with their coat coloring, or make Celestia dark skinned and Luna light skinned to match up how someone who was constantly under their respective heavenly bodies would look.

When it comes to humanization, I never really understood why so many people envision Twilight as a black teen. I just never really saw her that way, even with the darkish purple pony fur I just always felt like she would be a white chick or at least light-ish skinned as a human.
 
Celestia, on the other hand, I really can’t decide what kind of humanization feels the most natural for her, to me. I can really dig her as either a creamy mommah or a dark skinned sun goddess. I think something between the two like this seems like a great fit, this looks like a great design for her.
 
Not to mention the absolute MOM BOD :o

Perfection!