In terms of physical characteristics, ethnic Mongols exhibit a variety of features, with typical Mongoloid features being most noticeable. Epicanthic folds of the eyes exist on almost all Mongols along with high and pronounced cheekbones. The vast majority of Mongols have black hair and brown eyes, although a certain number of ethnic Mongols, particulary Mongolians of Western Mongolia tend to exhibit lighter features such as light to dark blond/brown or red hair, fair skin, and blue or green eyes.
If by Mongol it means Mongol national, it is obvious that they are not neccessary born in yellow skin color.
In science, skin color or "race" is in gradient. It is near impossible to define a race in science.