Q.Cause of yellowish needles on Fat Albert Blue Spruce
Our Fat Albert is 6′ tall. Only the tips of branches are bluish green. All interior needles have a yellow cast. It is watered almost daily (during growing season) by lawn sprinkler. Soil is moist, but not soggy.
Certified GKH Gardening Expert
There are a couple of needle cast diseases that commonly afflict blue spruce trees. Read about them in this article: https://www.gardeningknowhow.com/plant-problems/disease/needle-cast-in-trees.htm
I would suspect it is getting too light of watering too often. They do better with deep watering less frequently.
There are fungicides that can save your tree, but I would suggest contacting a certified arborist for help.