The USA was mostly colonized by Germans, Irish, and English. So skin tones are usually much lighter.

Central and South America had a larger indigenous population, and the Spanish/Portuguese colonizers had a bit darker skin, with much more frequent inter racial relationships.

However, the region in question is fucking huge. Don’t expect Mexicans, Columbians, Argentinians to all look the same.

Really Hispanic is more of a cultural category for all things with Spanish Legacy.