they are not.
Some people have naturally darker skin than others. It all depends on what genes you end up with. Some white people have naturally darker skin, and some black people have naturally lighter skin.
Because of shadows made by craters.
It's the amount of melanin in their skin; some have more than others, thus they are darker than others.
Mostly red and gold, some people make theirs a little lighter or darker than their hair. tip, most people like the darker color in the front than light than back to dark ect.
Vegans are not necessarily better than other people. Some are healthier than other people, and some are not.
This shade is noticeably darker than the other.
Other way around
They are colder and darker than the other areas
My skin has a lot of melanin. Melanin is responsible for darker skin colors. Whiter people have less melanin than darker people.
Because they are thicker making it hard for light to travel through
Because the lighter the pigment in your skin the less protected you are
They are features that are darker than other features such as if you were in a cave and the far side is darker than the other side than that is the low level image feature. ( they can be in any rainforest and in any caves or oceans.)