stand out like a sore thumb

Từ điển Oxford Advanced Learner 8th

stand/stick out like a sore ˈthumb idiom
to be very noticeable in an unpleasant way
•The blue building stood out like a sore thumb among the whitewashed villas.
•If you wear a suit to the party, you'll stand out like a sore thumb.
Main entry: ↑sore_idiom