>>507952762 (OP)The same reason Benjamin Franklin said the rest of Europe except for the British and Nordics were swarthy. Most people use to spend a lot of time in the sun. It wasn't until recently that people have better sun protection and jobs inside. Making skin colors paler overall in countries with more inside jobs are common.
The natural skin color for East Asians is a more paler color than some other groups if they don't go out in the sun., but they easily tan, creating a more yellowish look.