Blue body symbolizes blue eye color that comes from the body, not paint. Red, brown, yellow, black, & white are natural bodily hair colors of the white race.
That whole idea there would only really make sense if zero pharmaceuticals or surgery are allowed for anyone over age 49.
If reaching elderhood & white/gray hair is from a combination of good genetics and good lifestyle then the place with the elders will be elite.
Within that plan it might work best to have those with non blue eyes at the edge of the territory closest to the equator, & blue furthest. Then you just switch hemispheres to find someone foreign with the same eyes & hair, if that's what you want.
Australia brown & blonde.