The Cairn Terrier comes in a variety of colors. All are attractive, and you will love your Cairn Terrier whatever color he turns out to be. It can be difficult if not impossible to predict adult color based on the puppy coat. Color changes in many Cairn Terriers continue for years, most brindles eventually becoming very dark, bordering on black. Some wheatens and reds also darken while others may remain light.