For me, the hue would be a true blue, neither too green nor too purple. Also, I would expect it to be a clear blue, not muddy. So quite saturated, but also very bright. So a pastel blue, perhaps shot with streaks or splashes of white.

Also try searching for "glacier."href> Lots of wintry blue shades there!

I think of a light -- but not TOO light -- cool blue. Kind of an 'icy' blue. Like Maryliz says it would be pretty clear/saturated. I'm just getting image off the top of my head from Christmas cards and fabric.

Here are a couple fabrics I found online described as 'winter blue' and they vary a little but you get the idea.

The lighter blue in this is what I think of:
http://www.craftconn.com/Main.asp?Task=Custom&Step=Fabric+Details&productID=11280

OR see the link below...

Hopefully your birthday girl will see your question and send an example!

Here is a link that might be useful: snowmen on Winter blue

I always think of 'winter blue' as the kind of blue the sky is on a nice, sunny snowy day, when the sun is shining and it's reflecting off of everything.

~ Kit

Could you ask the person who requested "winter blue " to post something in the color?
Sally

I got a reply to my second email to the birthday girl yesterday afternoon. She was happy with most any blue to remind her of winter so I went shopping with your descriptions in mind and picked a Moda Marble in bright, light blue which icier blue marbling. Cut but haven't sewn block together yet but I think it'll look pretty. So that star will maybe look like it's snowing on a partially sunny winter day. I know it can rain when the sun is out so why not sunny and snowy too as Kit says. lol. Thanks for your help.
Ginny