Mighty Morphin Power Rangers
In the first season of Power Rangers, the Sixth Ranger is the Green Dragon Ranger, Tommy Oliver (Jason David Frank). Tommy is a new student at Angel Grove High, and he entered a martial arts tournament that Jason was in. The two fought, Tommy showing that his fighting skills were equivalent of Jason's. This caught the attention both Kimberly, the Pink Ranger and Rita Repulsa. Rita captured him and, using the special Green Ranger powers she possessed, cast an evil spell over him, turning him into the Green Dragon Ranger.
In his first encounter with the Rangers, he defeats them easily. After continued attempts of trying to get to the Tommy underneath the ranger, and succeed. Jason destroyed the Sword of Darkness, the source of the evil spell over Tommy, allowing him to join up with the other rangers, becoming the first ever Sixth Ranger.
After Rita's continuous streak of losses against the Power Rangers with the help of Tommy, she set out to get back the Green Ranger powers she believed were hers. Using a special green candle, she slowly drained the Ranger powers from Tommy. Jason tried to enter the Dark Dimension where it was held, as well as where Tommy was being held prisoner, but he couldn't get there because of the relentless monster attacks by Rita. As Tommy's powers faded, he transferred the Dragon Powers to Jason to keep Rita from getting her hands on them.
He left the rangers for a short time, but came back after Rita kidnapped the parents of every student at Angel Grove High. He still had the Dragon Power Coin and morphed, knowing that each time he morphed it would weaken him. Zordon granted him a temporary power boost so he could continue to morph. But, Lord Zedd ultimately destroyed his powers, permanently.
Tommy spent awhile away from the Rangers, but after Zedd unleashed his Nimrod monster, Alpha 5 and Zordon knew it was time to make a new Ranger. They made Tommy the new White Ranger, a ranger whose powers couldn't be used for evil. He wielded his talking sword, Saba to summon the White Tigerzord.
Mighty Morphin Alien Rangers
Delphine, portrayed by actress Rajia Baroudi, is the White Alien Power Ranger and leader of her team. She was the first female in the series to lead a team of rangers and is shown to be more durable than her fellow teammates. Delphine is from the planet Aquitar and commands the White Shogun Zord and the White Battle Borg.
Power Rangers: Wild Force
Alyssa Enrile, portrayed by actress Jessica Rey, is the White Wild Force Power Ranger. Alyssa was the second person to join her team, represents the noble tiger and commands the Tiger, Deer and Elephant Zords respectively. She has a kind heart, is nurturing and is often times the peace keeper between her fellow teammates. Alyssa is also the perfect student at school, boasting a perfect GPA, and takes dance classes to stay active. She is the first Asian to be a White Power Ranger.
Power Rangers: Dino Thunder
Trent Fernandez-Mercer, portrayed by actor Jeffrey Parazzo, is the White Dino Thunder Power Ranger. He is the adopted son of a multi-billionaire and has a very dark past due to the death of his parents. Trent is a bit a loner and can be very mysterious, often times reminding Tommy Oliver of himself when he was in high school. Trent represents the Stegosaurus dinosaur and commands the Stegozord and Dragozord, respectively. He has camouflaging powers when unmorphed. He is the first Asian male to be a White Power Ranger.
Power Rangers: SPD
Sam was originally a lonely boy with no friends, who couldn't fit in the other kids. As result he was constantly bullied and made fun of for being different. Sam had the genetic ability to teleport objects as well as create illusions, something the other kids teased him for. Though he was misled into joining the Troobians, he rewrote his wrongs and joined S.P.D as a young cadet. 20 years later, Sam would grow into the S.P.D Omega Ranger, travelling back in time to assist the S.P.D with their crisis in hopes of changing the future. As a boy he was eagerly excited to become a power ranger and as an adult he had developed an optimistic outlook, following orders without question and using his brain more than the rest of his team. Being the Omega Ranger, Sam wears a wrist-mounted Omega Morpher, a highly advanced futuristic S.P.D technology. He also pilots the Omegamax Cycle which can transform into the Omegamax Megazord.
Power Rangers: Mystic Force
Udonna was once a powerful sorceress, the loyal wife of Leanbow and mother of Bowen. After the Great Battle of Good and Evil, she lost her husband and son, spending the next several years alone with her niece Claire. When dark magic arose she chose five teenagers to fulfil their destinies of becoming the Mystic Force. Udonna became the White Mystic Force Power Ranger wielding her mighty Snow Staff into battle. Though she lost her Snow Staff to Koragg near the beginning of the season, she would later reclaim her artifact, becoming the powerful sorceress she once was. She would later reunite with her lost husband Leanbow (Koragg) and her son Bowen (Nick Russell) after many years of separation from them and become a family once again. Udonna is a caring and wise mentor to the Mystic Force during the first arc.
Power Rangers: Jungle Fury
Dominic Hargan, portrayed by actor Nikolai Nikolaeff, is the White Jungle Fury Ranger. Dominic represents the Rhino and commands the Rhino Steel Zord. He has to constantly prove himself because the other rangers do not take him seriously, and for a good reason too. Despite being a solid martial artist he can very lazy and is a bit of slacker.
Power Rangers: Ninja Steel
Haley Foster, portrayed by actress Zoe Robins, is the White Ninja Steel Power Ranger. She is an adventurous, out doors kind of girl. Zoe loves nature, healthy living and animals, as evidenced by her owning a pet husky. She is the girlfriend of Calvin, the Yellow Ninja Steel Power Ranger, and commands the Kodiak Zord, based on her pet husky. She is the first African American to be a White Power Ranger.