Hello Darren Marshall,
The issue about creating snow maps and snowy atmosphere settings in CoH1 is that there are almost no appropriate snow textures. The ones we have are custom made - everything else had and still has to be done with sand textures. The nature of the latter makes them come with a slightly yellow colour though - which isn't too snow-like.
Our workaround (which is the common one) is changing the lighting to achieve a snowy, cold and frosty look. Sadly, the saturation of a map is affected when doing that because getting rid of colours other than white and blue is hard to do without it.
What you might be interested in as well is the separation of environment lighting and soldier lighting. These two different entity groups may be affected by different light sources, colours and so on - thus it may seem like the map being black and white here and there, showing your units in much higher saturation that their surroundings.
I'll see what I can do about that, I'll surely try to duplicate the sunlight over the soldier light for the two maps having this odd look.
Thanks for reporting as always!
Best regards,
Max, Lead Level Designer.