Colour in Mars?

Hey guys, quick question:

In general, what size scope do you need to be able to see colour in the features on Mars? I usually get maybe three or four different hues: Bright white for the SPC, dark brown/gray for the darker features, and something approximating peach or salmon pink for the rest. But last night I was watching Syrtis Major appearing 'round the preceding limb, and I noticed a decidedly turquoise cast to it, although it was admittedly faint. I'm using Heep (my 'umble department store 4.5" f/8 Newtonian). Is such a thing possible? Or was I imagining it?

Clear nights ... dark sites,
Darren

Darren,

Mars is so big and bright these days, I would think that it is entirely possible. I generally see the darker markings as a bluish-greenish gray, but I'm using a bigger scope (8").

One thing to look out for is atmospheric dispersion. I'm at 42 degrees north, so Mars barely makes it up to 30 degrees altitude these days. I always notice a slight red coloration around the southern limb, and a slight blue coloration around the northern limb. But since you said that SM was just "appearing 'round the preceding limb", that would put it nearly half way between N and S, so that's probably not what you saw.

Regards,
Doug