User blog comment:Mrob27/Astronaut Wrangling/@comment-65.35.134.179-20120627193909/@comment-4583259-20120802032129

I've noticed that all astronauts change in brightness based on whether they're close to a Mini_Light or some other light source. Like in this picture, look at the blue astronauts here:



One is climbing the wall, and he's brighter (lighter-shade of blue) because he's close to two lights. Look in the other pictures above and you'll see other examples like that.

So maybe your gray astros are gray because they're never lear a light source.