@mimicking Well... For me, it's like this, since the protagonist lives in a northern European style setting, she would have white skin, but due to the dark spirit protection she has brown skin, due to the light spirit powers being antagonistic to the dark spirit, her blessing actually diluted the effects of the dark spirit protection on the protagonist skin instead of whitewashing (even more so because the 'heroine' skin is caucasian white and not albino white since nothing is mentioned about her skin is a different white from a usual northern European skin color), to the point that in the web novel, the protagonist says that her skin is still brown, but it's only a lighter color of brown (in the milk sense it would be like you have a glass of chocolate milk and you put white milk in it, the color would become lighter but it would still be brown, that what happened to her skin).
Also, it's implied that it's not due to her skin color, but due to her spirit protection (that is know because of her skin tone) that she's isolated from the rest of society due more to the extent her powers can achieve (that it's a lot, especially in the war potential), because of the story of the friend of the founder having the d.s.p (I got tired of writing it every time) creating a curse on the kingdom on his death, that was cleansed by a woman who had the l.s.p, but the guy with the d.s.p only did that because he was betrayed by everyone because everyone unjustly accused him of trying to betray the founder and take the kingdom for himself, who was his friend and also accused him of betrayal so the guy with the d.s.p did a very big f*ck, you guys! in response leading to the protagonist being feared and isolated
P.S: If I'm not wrong the blessing she receives from the LIGHT spirit, not holy spirit, the light spirit is only called holy because of the story I just quickly resumed