The red vegetation is the
xenofungus. The game has a really well-developed back story according to which xenofungus covers large swathes of the planet in several meters thick, almost impenetrable mats. The fungal mats form a planet-wide web which is actually a sort of semi-sentient planetary brain (Cameron 'used' the same idea in
Avatar 
).
However Chiron (simply called "Planet" by the colonists) is no paradise. It is larger than Earth and has a 30% stronger surface gravity and 70% denser atmosphere, which unfortunately doesn't contain enough oxygen for humans to be able to breathe comfortably (at sea level, there is just barely enough oxygen in the air). It doesn't matter though because the partial pressure of nitrogen makes the air mildly poisonous - humans without pressure helmets or nitrogen filter masks suffer of nitrogen narcosis similar to that which sometimes affects scuba-divers on Earth. First it's comparable to being mildly drunk, but then you lose consciousness and die. The air also contains various nitrates (which are a product of the native life's strange biochemistry) which break down ozone, so the planet doesn't have any ozone layer to speak of - and the dense troposphere only partially offsets this. (and so on, as I said the back-story is rich

)
The game files also contain basic information concerning the orbital parameters, rotation periods, moons, etc. of Chiron and other planets. I am trying to make an add-on using this info, but I struggle with the orbital planes and the rotational axis - I need the orbital plane of Chiron to be roughly the same as the orbital plane of the two Alpha Centauri stars (since simulations show this is necessary for the orbits to remain stable), unfortunately in Celestia the orbital plane of the planet is perpendicular to that of the stars. When I tried to align them, I found the planet's rotational axis was totally off, like that of Uranus in our solar sytem. It's kinda frustrating since I don't really understand how Celestia works in this respect so I am doing it in a trial-error manner. Any help here would be appreciated.