Here is probably a dumb question, but what is the difference between the colors of the Artic Armor other than the colors? Since they show it as seperate items I wondered if that meant they had different features? Also is this something that you need to layer underneath? I am considering Ice Armor Blues to also be able to wear them in the spring steelhead fishing and fall for salmon, would A/A fit that bill too or is the insulation value to high? Thanks.