Spruce decline has been rampant throughout Michigan for better than a decade, especially for Colorado Blue Spruce. There are a number of needlecast diseases,
cankers, insects such as mites, among others that are responsible and often it is more than one of the above stressing the same tree. Read more here:
And here: https://www.canr.msu.edu/news/what_is_spruce_decline_and_what_should_you_do_about_it
We strongly recommend an onsite evaluation by a Certified Arborist, who will be well versed in spruce issues because they have become so common. You can find one or more Certified Arborists in your zip code at www.treesaregood.org Click on the Find an Arborist tab. Arborist evaluations are not expensive and where you can learn exactly what is going on in your tree and what to do about it. These things do not get better on their own and will progress to death without intervention.