The answers to the clues below will have something in common.

1. Brain power

2. Very infrequent, rare 

3. Memorable, as a day

4. Bring lunch to work

5. Seller of fruits and vegetables 

6. Symbol of welcome and support 

7. Special message for a missing child

8. Positive side of a negative experience 

9. One who has gone astray from family traditions 

10. Termination notice or automobile ownership proof 

11. Useless, often expensive possession that's hard to get rid of  

 

Answers: 

 

1. Gray matter

2. Blue moon

3. Red letter

4. Brown bag it

5. Green grocer  

6. Yellow ribbon 

7. Amber alert

8. Silver lining

9. Black sheep

10. Pink slip

11. White elephant