Well, just happened by and yes, I am a skier, it so happens. I have been skiing since I was a kid and that was a very looooong time ago. To put it in context, leather ski boots, wooden skis and cable bindings were the norm when I began. Yes, that long ago. I'm perhaps somewhat atypical in that I ski both Nordic (or cross country, if you prefer) and alpine (or downhill, if you prefer).
Insofar as clothing is concerned, and since the OP was apparently interested in alpine skiing, the question asked is actually far more difficult to answer simply than it might seem to the uninitiated, and not because of the time over which I have been involved. There has always been more than one category of skier beyond skill levels. First, there are the social skiers who obviously are interested in the social aspects of skiing as much or more than the actual skiing itself. Then there are the hardcore skiers that could care less about the social aspects or only participate in that once the lifts have shut down. They are the first up the hill when the lifts start, and almost the last down the hill at the end of the day, save for the ski patrollers doing their sweep. For them, its all about the skiing. Then, last and least, you have the competitive skiers. Each of these groups, with some variation, tend to have their own uniforms or style of dress.
The social skiers tend to spend a lot on ski outfits and, at the risk of sounding a little harsh, it can be quite the fashion show. Lots of colour, lots of flash. Colour co-ordination and lots of money. Of course there are exceptions, to be fair. I have seen one piece suits and two piece suits of just about every style and colour. The only way to really get a sense of it all is to either spend a day perusing the lift lines, or look through a catalogue. Googling ski equipment is your best bet and anywhere that they sell such will include a wide selection of clothing to go with.
The hardcore types will tend not to worry as much about appearance and choose their clothing much as they choose their equipment: performance comes first. As a consequence, they tend to be less showy, and usually wear more conservative hues. For cold weather, a ski parka or jacket over a pair of bib ski pants is pretty standard.
Lastly, the competitive skiers, at least while they are skiing, have onepiece, skintight racing suits that are pretty standard, and these are usually extremely flashy, often reflecting their ski team and sometimes emblazoned with their sponsors advertising - the human version of race cars.
So, there can be a lot of variation out there and much depends upon what you wish to depict. You wouldn't show someone in a downhill race wearing a two piece snowsuit.
Lastly, there is the special case of the proverbial ski bum. These guys don't care what they wear, as long as its warm enough. For example, most of my life skiing, you would tend to find me wearing a pair of blue jeans over long johns, a sweater and a short jacket. On occasion, I'd freeze my butt off, but it was just part of skiing, for me. I do own a pair of insulated ski pants, just in case I ever decide to actually wear them. They work great for shovelling the driveway. I also have a rather expensive down-filled parka that I like to keep for special occasions. Hate to get it dirty. Oh, and the ski pants are navy blue while the parka is forest green and I could care less. Oddly, my usual ski jacket is burgundy which actually co-ordinates quite well with my blue jeans. Not sure how that happened.
Now for Nordic, well, that's a whole 'nother story.