My Blue Spruce Tree

Please! Can anyone tell me what's wrong with my tree, I am devastated!  Okay, this is what I believe happened. My husband was spraying some of our plants and shubs for insects near the house. Upon his completion, his eyes fell upon this lone tree in the distance. With gun still in hand, wanted to make one last kill (pun intended). Now I know our guys so want to be as helpful as they can but, can sometimes go a little overboard. I've been growing this tree for five years. It started out as a little thing, slow growing but healthy. I noticed a week ago that it was only blue at the tips and light green everywhere else.  This is the picture I took this morning! I really want to cry but I don't want to give up hope. Now even though the tree is terribly discolored, the needles are just as strong and feel the same as the blue tips on the ends. The tree is not shedding when I pull my hand up the branches forcefully. IS THERE ANYBODY OUT THERE THAT CAN GIVE ME HOPE?