The Blue and the Gray is the thirteenth episode of Season 22.
Marge discovers her natural gray hair, and Homer becomes a Valentine's Day wingman to Moe, much to Marge's suspicion that Homer is cheating on her.
After spending another Valentine’s Day alone, Moe attends a seminar led by Dr. Kissingher in the hopes of gaining more confidence with women. Moe takes the doctor’s advice and asks Homer to be his wingman, but Moe becomes distraught when women are drawn to Homer as well.
Meanwhile, Marge discovers what she believes to be her first gray hairs, only to be amazed when her stylist reveals that she is actually 'completely gray' but the fumes of her weekly dye job remove any memory of this matter. She plans to go gray now and surprises both her family and the neighborhood by sporting a brand new mature ‘do'.
Unfortunately without her signature color, Homer no longer finds her hair attractive. Bart is not humored when the neighborhood kids tease him about Marge’s new look. At the grocery store she is joked by Luann Van Houten, Edna Krabappel and Bernice Hibbert, and strangers believe she is elderly, with the cashier at the grocery store asking if she has a discount from AARP and a barista telling her someone her age shouldn’t have caffeine. Later, Marge confronts Homer when she learns that he is becoming increasingly popular with the young ladies, but Homer helps Marge realize that he only has eyes for her, although he does have a “type“ when it comes to hair. Marge has her hair dyed back to blue to combat her jealousy issues, and Homer dyes his hair blue for her.