put the roses back in (one's) cheeks
To make one appear more vigorous and healthful than they did previously; to return one to a healthy complexion. Nothing will put the roses back in your cheeks like a trip to the seaside. After a long day, I like to drink a glass of red wine to put the roses back in my cheeks.
put the ˈroses back in your cheeks
(British English, informal) make you look healthier because you are not so pale: A week in the countryside will put the roses back in your cheeks.