Use atmospheric parameters to color eclipsed objects

[LukeCEL]

Is your feature request related to a problem? Please describe. When the moon passes behind the Earth, it gets colored red due to the Earth's atmosphere, but that's not shown in Celestia.

Describe the solution you'd like Celestia could use the atmospheric parameters of the eclipsing body to color the eclipsed body.

Additional context This is probably a relatively low-priority change.