A Happy Flashback is pretty much Exactly What It Says on the Tin, a Flash Back to a happy time in a character's past. Frequently they have a drastically different color palette from the rest of the film/tv show in keeping with most Flashbacks. It'll be very bright, warm and colorful (possibly even supersaturated with color) or almost completely white from the brightness, or in simple sepia tones with blurriness added. Then again, it might be drawn in crayon to really invoke the "good old days" feel.
The Happy Flashback is often used as a mood counterpoint in a scene that is decidedly dark. It especially helps when the entire story is very sad or even tragic because it provides a "breather" for the audience and helps avoid Darkness-Induced Audience Apathy. It's similar to Comic Relief, with the benefit of adding Backstory and helping to breathe some hope back into a character or plot. The emotional counterpoint is especially useful for storytellers since it serves to show that the character(s) aren't walking bags of Angst, they can feel other emotions and the pain they feel now is all the more keen because they once were happy.
- In Bleach Soi Fon has one of these, during her fight with her sempai/possible love interest, Yoruichi. During their time together, we see a younger, happier Soi Fon. At least, she was until Yoruichi betrayed her trust and devotion when she ran off with Urahara Kisuke. Soi Fon swore vengence for this, leading to the person that earned her the Fan Nickname "Captain Bitch-Ninja".
- This happens twice in Chrono Crusade, both times leading into a Troubled Backstory Flashback. Early in the series there's a flashback that shows Rosette's childhood with her brother, Joshua, as well-taken care of orphans who spend their days picnicking and playing before Joshua is kidnapped by the Big Bad. The second time it happens is when Chrono flashes back to when he met Mary Magdalene, whom he fell in love with but accidentally killed when he made a contract with her after he betrayed Aion. In the manga version, Rosette even wonders to herself if Chrono attempts to go back to those happy memories in his dreams.
- The Saint Beast OVAs as a whole are meant to be this, although they are tinged with hints of darker things to come.
- Gundam Seed Destiny dedicates an episode to establishing Shinn's carefree civilian life in Orb and how he really wasn't interested in politics and war, featuring one of these...followed immediately with the Battle of Orb.
- In the Red Robin/Batgirl Collision crossover, Red Robin gets a couple of himself and Batgirl. Just as an assassin named Prudence, who's life he saved, and who he neglected to immediately incapacitate, is pointing a gun at Batgirl's head and saying she was ordered to kill her. The flashbacks include a nice one with a pink background of him and Stephanie kissing, and Tim blaming himself for getting someone else killed.
- Of course, Bat-Steph then proceeds to hand Prudence her ass, so the tragic contrast is almost hilariously subverted two seconds later.
- This happens twice in Batman Begins, with Bruce Wayne reflecting on times with his father in at least two separate scenes from the movie. The first is long before Bruce takes on the Batman identity, when he is planning to take revenge against the murderer of his parents. The second is after the climax of the movie, in the second-last scene of it. This is done to contrast the attitude Bruce had at the former time with that he had at the latter time. The first leads into a Troubled Backstory Flashback.
- In Pandorum, Bower has happy flashbacks to his life with his wife back on Earth. Subverted when it turns out that she decided not to go with him to Tanis and left him.
- The Road contains a few flashbacks to the pre-apocalyptic family life of the protagonists.
- (Please confirm)[please verify] Happens in Shutter Island. Some of the flashbacks have a more surreal, symbolic value and far from all of them are happy (but some are).
- Jill Tuck has one in Saw: The Final Chapter
- At the end of Godfather 2, there is a somewhat happy scene showing the Corleone family sitting around the dinner table, as Michael tells them he is joining the Marine Corps and going off to fight in World War II. This represents the end of the happier, together times in the Corleone family's life, and Michael's transition to the lonely, ruthless man we see him as at the end. This is counterpointed by the final shot of Michael sitting alone in the Lake Tahoe compound.
- Shallow Grave ends with one flatmate dead, another stabbed and uncertain about his fate and a third discovering they've been cheated out of the loot. Cue Happy Heart rolling over a repeated sequence of the three flatmates earlier in the movie, laughing and hugging. Wham.
- Jericho, in a decidedly dark episode about a war with nearby town New Bern, has multiple flashbacks from Jake to the day of his brother's wedding.
- In Monk, all of his flashbacks with his wife Trudy. Averted with his childhood memories, which are awful.
- In Buffy the Vampire Slayer, used extremely effectively in season 7 by going back to a scene we didn't see from the beloved Musical Episode from the previous season.