Kamehameha is a commonly used Energy Wave throughout the series. It makes its debut in the first Dragon Ball series. The Kamehameha is formed when cupped hands are drawn to the user's side and the ki is concentrated into a single point between the cupped hands. The hands are then thrust forward to shoot out a streaming, powerful beam of energy. This technique is among one of Goku's signature attacks. Goku first used this attack in the episode, The Kamehameha wave. He blew up a car when he first used Kamehameha wave. This attack was invented by Master Roshi.
After much contemplation, Akira Toriyama could not decide on a name for his "Kame" attack, so he asked his wife for ideas. His wife came up with the name and the stances used during the attack. She also told Akira that it would be easy to remember the name of the attack if he uses the name of the cultural Hawaiian king named Kamehameha. Akira agreed, and the Kamehameha was born.
The Kamehameha was invented by Master Roshi by practicing fifty years spanning pre-Dragon Ball. By drawing his latent ki into the palms of his hands, Master Roshi was able to expel an explosive beam of ki energy. Goku learned it after witnessing Master Roshi unleashing the blast to extinguish the flames at Ox-King's home on Fire Mountain. To Roshi's surprise, Goku successfully performed the technique on his first attempt, although it was only strong enough to destroy the car that Yamcha gave to Bulma. It was also learned by Krillin and Yamcha who used it during the 22nd World Martial Arts Tournament against Chiaotzu and Tien Shinhan respectively. After they learned the attack, they taught it to others, and the attack became a very popular one to use during battle. Cell is also capable of using it due to the cells of all these people within his design. Majin Buu learned the technique after seeing Goku do it during the Majin Buu Saga.
The Kamehameha is formed when cupped hands are drawn to the user's side and the ki is concentrated into a single point between the cupped hands (and the hands must be really close), however in the manga, there aren't any energy spheres in user's hand. The hands are then thrust forward to shoot out a streaming, powerful beam of energy. The blast can also be used, generally under extenuating circumstances, with just one arm or even the feet. In most variants, the user utters the word "Ka-me-ha-me-HA!!!" as he/she charges and releases the attack. Master Roshi's Kamehameha is called the Original Kamehameha in the Budokai Tenkaichi video game series, and requires some time to charge.
The Kamehameha has several different colors in the anime, movies, video games, and manga. The power and concentration of the different types of Kamehameha also vary greatly. Whitish-blue is its standard and original color. When Goku is in his Super Saiyan 4 transformation, his 10x Kamehameha is red-colored, Gohan's Ultimate Kamehameha in his ultimate form, is yellow. In some games and episodes of Dragon Ball Z, the color of Goku's Kamehameha color is yellow instead of the primary blue color, and Super Saiyan Vegito's Final Kamehameha is yellow or golden yellow, while it remains blue when Vegito is in his base form. Majuub's Chocolate Kamehameha has a pink color (but was blue in it's debut). Majin Buu's various forms can also use the Super Kamehameha , which also has a pink color or the original blue color.