Billy Dengler's favorite color is orange.
Like the bright, shiny peel of the fruit, or the blazing hue of a sunset, or the luminous wings of a monarch butterfly.
Yet Dengler, 14, has never seen those things. In fact, the eighth-grader has never even seen orange. He does not know what orange looks like. He does not know what orange means.
Dengler is blind.
But his mother made him pick a favorite color in first grade because that is what first-graders do.
Although Dengler can't see, he has never let that hold him back or make him different in the "sighted world" that he lives in.
"Being blind is not a disability," he said. "It's just an inconvenience."
An inconvenience that hasn't stopped him from playing junior G-man or exposing bugs in the programs of a global Internet giant.
'A DIFFERENT WAY'
When Dengler was born in October 1999, his mother, Terri Dengler, did not know her first child was blind. It wasn't until a month later when Terri noticed Billy's eyes weren't quite as big as a normal baby's.
Terri's intuition was correct.
When he was just a few months old, Billy was diagnosed with Norrie disease at the Kennedy-Kreiger Institute at Johns Hopkins. This genetic disorder causes blindness in both eyes of male infants, according to the Norrie Disease Association.
Billy would never be able to see.
At least, not with his own eyes.
After Billy's diagnosis, Terri began talking to him, describing things she saw. She told him what she was cooking, or what she saw out the window.
"I tried to explain everything to him," Terri said. "And I tried to learn as much as I could about the blind world, because that was my son and I wanted to learn everything about it."
She said she sometimes would become frustrated thinking that Billy wouldn't be able to play with different toys or see fireworks. But then Terri thought that fireworks make a really great sound.
"There is always a different way around it and a different way to experience something," she said.
Billy does not simply rely on his mother's descriptions to discover the world around him. He sees with his ears and his hands, too.
He has perfect pitch hearing -- somewhat to the chagrin of his choir teacher, who gets corrected by Billy when he sings an off note, Terri said.
If someone drops coins, Billy can say how much change fell based on tones made by different coins striking the ground.
He also can tell what number someone dialed on their phone by distinguishing the distinct tones for each number. In fact, Billy's gift has helped the Federal Bureau of Investigation by listening to recordings and telling them what phone number was dialed, his mother said. The FBI discovered his talent when he met a technician at one of the many technology conventions he has attended.
"His adaptations for his visual disability are so amazing," Hilton Head Island Middle School principal Greg Stickel said. "He is just so inspirational with his attitude and is so intelligent, he truly is one of a kind."
Billy's social studies teacher, Steven Moe, agreed.
"He is very confident in himself and he doesn't allow his handicap to keep him from being a part of the class and an important part of the class," Moe said. "The students love him, and he is just one of them."
Except that he is not.
Billy began teaching himself computer coding and programming when he was just seven years old. He now is a certified Google and Apple developer, he said.
Google even tried to offer him an internship last year when he discovered a bug in one of their systems, but Billy wasn't old enough, Terri said.
"They said, 'You are the exception,'" Billy said. "They said, 'You doing more than most blind people would normally be doing and more than most sighted people would even be doing.'"
A CONQUERING ATTITUDE
"It's a sighted world," Billy said, and he is determined to succeed in it.
"I have to constantly come up with ways to get around limitations, but I have the attitude that I will conquer this and go on to the next thing."
He said he tries to avoid devices for people who are blind, although he uses a screen reader -- which he sets to read at a rate of 300 to 500 words per minute -- for his iPhone, Macintosh computer and other devices.
Billy's dream schools would be Stanford University or the Massachusetts Institute of Technology, where he could get a top education in computer science. He earns top grades in his classes, making that a real possibility.
Whether he will go to work at a tech company like Google or design a software company of his own is still to be decided.
But he definitely will do something great, his step-father Bill Rupp said.
"People are given obstacles in life, but I think God probably gave him the gift of wiring him a little differently and his other senses are probably a little stronger than would be normal to overcome it," he said.
"We don't use it as an excuse," he added. "You can't let excuses get in the way of your dreams, and if you do that you can't move forward and accomplish your goals."
Terri said her son once asked her why he was blind, but in a tone of wonder, not resentment or anger.
"He once told me that if he could get his sight back, he doesn't know if he would want to," she said, "because he would have to learn how to see all over again; he sees with his hands and his ears."
Follow reporter Sarah Bowman on Twitter at twitter.com/IPBG_Sarah.