The blotchy appearance of skin color in the face and hands of older people is due to the uneven distribution of pigment cells and to changes in the interaction between melanocytes and keratinocytes. Sexual dimorphism
It has been observed that females are found to have lighter skin pigmentation than males in some studied populations. This may be a form of sexual dimorphism due to the requirement in women for high amounts of calcium during pregnancy and lactation. Breastfeeding newborns, whose skeletons are growing, require high amounts of calcium intake from the mothers milk (about 4 times more than during prenatal development), part of which comes from reserves in the mothers skeleton. Adequate vitamin D resources are needed to absorb calcium from the diet, and it has been shown that deficiencies of vitamin D and calcium increase the likelihood of various birth defects such as spina bifida and rickets. Natural selection may have led to females with lighter skin than males in some indigenous populations because women must get enough vitamin D and calcium to support the development of fetus and nursing infants and to maintain their own health. However, in some populations such as in Italy, Poland, Ireland, Spain and Portugal men are found to have fairer complexions, and this has been ascribed as a cause to increased melanoma risk in men. Similarly, studies done in the late 19th Century/early 20th Century in Europe also conflicted with the notion at least in regards to Northern Europeans.
African-American journalist Jill Nelson wrote that, "To be both prettiest and black was impossible," and elaborated:

We learn as girls that in ways both subtle and obvious, personal and political, our value as females is largely determined by how we look. ... For black women, the domination of physical aspects of beauty in womens definition and value render us invisible, partially erased, or obsessed, sometimes for a lifetime, since most of us lack the major talismans of Western beauty. Black women find themselves involved in a lifelong effort to self-define in a culture that provides them no positive reflection. A preference for fair or lighter skin continues in some countries, including Latin American countries where whites form a minority. In Brazil, a dark-skinned person is more likely to experience discrimination. Many actors and actresses in Latin America have European features—blond hair, blue eyes, and pale skin. A light-skinned person is more privileged and has a higher social status; a person with light skin is considered more beautiful and lighter skin suggests that the person has more wealth. Skin color is such an obsession in some countries that specific words describe distinct skin tones - from (for example) "jincha", Puerto Rican slang for "glass of milk" to "morena", literally "brown".In South Asia, society regards pale skin as more attractive and associates dark skin with lower class status; this results in a massive market for skin-whitening creams. Fairer skin-tones also correlate to higher caste-status in the Hindu social order—although the system is not based on skin tone.