I wrote by hand again
Would you believe I don't remember ever saying or writing "cheer"?! People announce CHEERS! as a toast. I know there used to be a TV show called cheers and I know I never watched it.
When John and the synoptic gospel writers have Jesus counseling us to be of good cheer as many English translations express it, that's telling us to have courage, literally to take heart. Heart-related words like cardiac and concord and concordia come from the same root as courage and courageous. In Hebrew biology the heart mostly is the seat of the will and determination, rather than the location of emotions as modern westerners have it.
I don't use the word cheer, but personally and as a designer I love the idea of cheerful colors, a bright cheer-filled space. I love the idea of cheering up a person with brights and lights of any kind.
PS As I somewhat recycled my cheer / courage header design from a couple of Valentine's days ago, I remembered a book called the Red Badge of Courage, therefore—cheer and courage in red!