Like Green Lantern, there have been several versions of this character. Focusing on the one who carried the title longest, Ted Kord was basically an athletic guy with a great sense of humor and some of the coolest gadgets on Earth.
Hovering above the city in his "Bug" (a flying ship), he was the inspiration for the Nite Owl character in "Watchmen". His death at the hands of Maxwell Lord was a catalyst in the eventual discovery of the OMAC project.
One of the original members of the Liberty Legion, Blue Diamond appeared in the 40's for real as one of the earlier obscure heroes in print.
His skin was diamond-hard (thus the name) which allowed him to take a lot of punishment on the way to dishing it out. He still appeared in comics up until the 80's, showing up in a Marvel Two-In-One comic.
Ultimately, he was turned into an actual diamond to help preserve his body since he was getting so old and traveled through space with an alien. Back on Earth, now he's pretty much disappeared from the radar.
This DC character has a strange origin. Originally, a stunt man put on the costume, only to find he couldn't remove it after an encounter with a real demon in a cave.
The character was originally played as a light-hearted Booster Gold type character, but that changed. The Blue Devil had his own series for a while, but has pretty much stayed in the background as a secondary character. As of late, he's joined up with some of DC's more supernatural crew (including Detective Chimp, who we never expected to see again) called Shadowpact.
He even made a quick cameo in the JLU figure line and has recently had a fairly nice DCU figure made of him.
Sally Avril wasn't around for long as a superhero, but she had spunk.
Originally deciding to become the official photographer of Spider-Man (until she found out Peter Parker had the job), she decided instead to become a hero of her own. She teamed up with Spidey a couple of times (not his choice) before he was finally able to talk her out of the dangerous profession.
Unfortunately for her, she was killed in a car wreck after giving up the superhero job while on her way to take more photos of Spider-Man in action.
This character was a member of the Squadron Supreme in their first incarnation during the maxi-series of the 80's. He had originally appeared as American Eagle before taking on his colorful moniker.
Unfortunately, his term as Blue Eagle was very short-lived. He was killed during a battle when Lamprey drained his wings of their power. He fell to his death.
This character is actually pretty cool, though mostly forgotten.
He has the ability to create a force field around himself and others, and is currently the director of the Pegasus Project, a position held by Quasar, among others.
He's probably the coolest thing to come out of the Dazzler comic series of the 80's (his origin was told in issue 5). Hopefully we'll see him pop up sometime in the future, though given Marvel's treatment of their older characters it's probably best he stays hidden for now.
Next week, we look at the absolute mother lode of comic book color name titles: Black!