Colors:
* Blue sky, blue ocean, blueberry, bluebird, blueprint, blue jeans
Emotions/States:
* Blue feeling, blue mood, blue collar, blue ribbon, bluegrass music, blue blood
Nouns:
* Blue whale, blue chip stock, blue cheese, blue Monday, blue box, bluebottle
Verbs:
* Blue themselves, blue the paint, blue the sky (as in a storm), blue the scene (as in a movie)
Phrases:
* Blue in the face, blue with cold, blue with sadness, blue as the ocean, blue as a smurf
Other:
* Blue light, blue shift, blueprints, blueberries, bluebottles
The possibilities are nearly endless! To get a better understanding of what words would work best, please provide more context about what you are trying to convey.