Just Like the Maher Star

[Commander Mick]

They say it's Brown Star, even though it looks purple.

 

[Mephane]

Yeah, a brown dwarf isn't actually brown, the name is to differentiate it from a red dwarf. Since brown is not even a color, but merely a very dark red, it makes sense to associate it with objects even smaller and dimmer than red dwarves.

I think I've also read somewhere that brown dwarves might indeed be dark purple, sadly I have no idea where and therefore cannot provide a link.

 

[Tacheel]

From what i've read they vary in colour from deep red (warmer) to dark purple (cooler) depending how far into their cooling process they are.

And invariably they are always very close to the size of jupiter. Larger or smaller wouldn't end up as brown dwarves.

 

[Karkarand]

Supposedly the atmosphere of a T-class brown dwarf will absorb some of the green light emitted, which would give a magenta tint if it was emitting white light. But since it's starting with more of a dark red due to the low temperature, this isn't going to make much difference - i.e. there isn't much green light to be absorbed, and even less blue light to be transmitted. So it almost certainly won't look anything like the garish artists impression above. The illustrations in the wikipedia article are probably rather closer, although possibly still overdoing it a bit.

Y-class dwarfs are too cold to emit anything much in the visible spectrum, so they'll just look like planets - you could probably argue that's pretty much what they are.