Alright, tell me the difference between these two:
1:
http://img15.exs.cx/img15/586/x7rfzicebox0003.jpg
2:
http://img108.exs.cx/img108/2989/k2wx7rfzicebox0003.jpg
You get the point? Ice doesn't always means little variation in colors. You could try the old icy map from CS 1.5 (don't remember its name, though - it is where you have that crashed airplane). That map is damn interesting with falling bridges, spectacular and varying visuals, cliffs, a town, and even the a-team van.
Your map is fine, technically, but you have some road to go through still until your maps look like the real pros' ones. I'm in the same boat as you are, actually, just learning... So keep it up!