Peach is a color that is named for the pale color of the exterior flesh of the peach fruit. Like the color apricot, the color called peach is paler than most actual peach fruits and seems to have been formulated primarily to create a pastel palette of colors for interior design. Peach can also be described as a pale, yellowish-pink.
Generally speaking peach is just a very light tint of orange or red-orange. It’s pretty easy to make in paints, just start with white and add a very, very small amount of red and a small amount of yellow until you get the tint you like. If you have cadmium red you can probably rely mostly on that since it’s practically orange right out of the bottle.
The etymology of the color peach (and the fruit): the word comes from the Middle English peche, derived from Middle French, in turn derived from Latin persica, i.e., the fruit from Persia. In actuality, the ultimate origin of the peach fruit was from China.