Answer
I would say "childlike glee" is the misplaced modifier,
Definition of misplaced modifier: A misplaced modifier is a word, phrase, or clause that is improperly separated from the word it modifies / describes.
Step 1: We know all firework give off brightness and color and it usually happens during the night, we can ignore those because those are proper.
Step 2: Now we have "awestruck crowd' and "childlike glee."
Definition of awestruck: to be full of complete wonder, amazement, or dread for something.
awestruck isn't a misplaced modifier because its not like nobody is going to ignore the fireworks-- everyone is going to look at them in amazement.
Step 3: Now we just have "childlike glee", it is a misplaced modifier because we are not sure what people (children/adults) are in the crowd. It wouldn't make sense if the adults gave a childlike glee so its a misplaced modifier.