Cosmetics or make up (gandhavilepana) are colors or perfumed substances put on the body for the purposes of beautification by masking blemishes and covering odors. In India during the Buddha's time, women and sometimes men too, put powder (kakku) and rouge (manosilā) on their faces, painted their lips, palms and finger tips with lac (lākhā), rubbed sandalwood powder or oil on their bodies (candana) and painted their eyes with collyrium (añjana, Digha Nikaya I.7; Ja.V,302; Thi.145; Vin.II.107). The Buddha's cousin Nanda, used to paint his eyes with collyrium, which in men was a sign of sophistication rather than of effeminacy. Smart young men would sometimes match the color of their makeup to the color of their clothes (Digha Nikaya II.96).
One of the eight Precepts which committed Buddhists practice on half and full-moon days is not to use makeup or personal adornment. Harmless in themselves, makeup and adornment represent the desire to make things appear different from what they actually are. At least twice a month serious lay Buddhists abstain from applying makeup and give themselves to recognizing, accepting and being content with the present reality. Monks and nuns are asked not to use ‘garlands, perfumes, cosmetics, ornaments and adornments’ for the reasons stated above but also because they require so much time and expense (Digha Nikaya I,5).
Cosmetics, for many is considered an art and for some Buddhists, art is seen as another attachment. While it is clear that a fully enlightened arahant may have little use and no attachment to mundane things like art, for other Buddhists and those interested in Buddhism, art can be a wholesome action and interest. The Buddha saw its value because he said monks and nuns could beautify their monasteries by painting them different colours and decorating them with various geometrical and floral designs (Vinaya 2. 117). As Buddhism spread in the centuries after the Buddha's passing his teachings gave an impetus to all the arts - painting, sculpture, poetry, drama and to a lesser degree music. There are Buddhist Vinaya rules against monks and nuns indulging in arts, shows, and games, but this rule does not apply to lay people. Monks and nuns are supposed to devote their lives to the study and teaching of Dhamma and it would look unseemly for them to be seen by lay people engaged in such things as watching movies, painting pictures, or discussing creative chess strategies.
Buddhists wear cosmetics, if they so choose, but do not use them during retreats and other days when they want to focus on their meditation practice. At other times, Buddhists use or don't use cosmetics at the same rate as anyone else in the community / nation. Lay people are allowed to wear make up and for those who like to wear it, the use could be considered a skilful means to non-Buddhists, showing that Buddhists do not shed all wealth or give up all pleasures of modern life.