Blue-blooded boys (5)
I believe the answer is:
royal
'blue' is the definition.
(royal blue is a kind of blue)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for royal that I've seen before include "Like Priam" , "Member of monarchy" , "Excellent" , "Relating to a sovereign" , "- blue; - assent" .)