Dreaming about your boyfriend painting his fingernails blue could symbolize a few things. Nail polish often represents self-expression and individuality. The color blue can be associated with calmness, trust, and loyalty, but it can also represent sadness or feeling blue.

This dream might suggest that you are processing your boyfriend's desire to express himself in a unique way, or it could indicate your feelings about his self-expression and how it affects your relationship. If you feel positive about the act in the dream, it may signify your acceptance and support of his individuality. Conversely, if you felt uneasy, it could reflect concerns about changes in your relationship or your boyfriend's emotional state.

Consider how you feel about the color blue and what it represents to you personally. Reflecting on your feelings and the dynamics of your relationship can provide deeper insights into the meaning of this dream.