Houghy - In Space ... no one can see you are dressed like a dork!!
and i am sorry to disappoint - but I always buy super cool trendy black ones

LOL
Phil is correct - always buy them a little bit oversize to fit clothes underneath if you can.
I am going to share with you my personal secrets that i have developed by trail and error over the years to keeping warm that allows me to stay comfortably out in the open till sunrise, and enjoy the show(s) without ever even thinking about the cold (except on rare occassions).
First - I start with board shorts - then thick quality trackie dacks over them - then cotton t-shirt close to skin followed by another thick acrylic/polyester t-shirt over the top of that (remember golden rule - synthetics sythetics synthetics - they dont breathe like natural fibres - so retains heat better) then a thin polyester damart long sleeved thermal top, then a thick synthetic long bottomed shirt - then put bib and brace ski suit over all this (with still room to move)- then a very thin (high quality - mountain climbers) polar fleece jacket over all that - then I bought from a mountain climbers shop an excellent (expensive - $200) sleeveless polar fleece vest (very long goes down pass my backside). And if it gets really cold i wear a huge road workmans wool coat over all that - on my feet i wear a pair of thick synthetic oversocks (I had left over from being a lumberjack (briefly) in Scotland that stopped your socks riding down in steel capped gum boots) over woolen explorer socks. And a quality pair of newish thick soled Nikes or something similar (i dont have moonboots yet) And of course an expensive quality special thermal material beanie.
There you have it - the colonels secret formulae
Of course there a thousand otherways to do this - my co-observers have their own set ups -Bazz swears a thick loose one piece pair of workmans overalls with two pairs of trackie dacks underneath - Stew swears by his 1000 dollar lightweight motor bike suit - lots of ways to skin a cat as they say
We have only been sprung twice dressed like this - once some roo shooters came up close with spotties on us one time - they were really nice but soon disappeared - we have made a few petrol station attendants speechless as well

. I have only wrecked one pair of cheap ski pants and that was coz of stitching coming apart
If you can handle lots of swishing noises as you walk - i reccomend ski suits - but I like the sound of the cold room overalls - thanks phil - will look into that

Cheers
Toasty warm Fringey