The Ultramen's appearance is based on The Grays and Mayan Ancient Astronauts. The red-and-silver colors are inspired by the legendary canals of Mars and a sleek space rocket respectively (Space Age idealism heavily influenced designer Tohl Narita), while their facial expression was based on Noh masks and the placid faces of meditating Zen Buddhists to emphasize their benevolence.
Despite being one of the most well-known traits of the Ultras, the Color Timer and three-minute rule was actually a last-minute addition when the writers for Ultraman realized the hero had no weakness, thus no way of creating tension or suspense in the fights.
The physical fighting style of the Ultras is inspired by Judo and Greco-Roman Wrestling, while the Christian Cross served as the basis for the position they hold their arms in when firing their beam attacks.
Of the 4 major Tokusatsu TV series,note the other 3 being Kamen Rider, Super Sentai, and Metal Heroes the Ultra series is the only one that has not had Jason David Frank audition to play a role in an American Adaptationnote Although this is mainly due to the fact that no Foreign Remakes have been made - aside from Power Rangers, Frank originally auditioned to play the lead in VR Troopers, and almost got the part of Len in Kamen Rider Dragon Knight; however, both cases were unsuccessful due to his involvement with Power Rangersnote In the case of the former, Tommy Oliver was so popular that the decision was made to bring Tommy back as a new ranger instead of giving Brad Hawkins a new character as originally planned; in the case of the latter, it was because the producers of Dragon Knight did not want people to associate the show with Power Rangers - ironically, the same year Dragon Knight finished airing, the then-currently-airing Kamen Rider series, Kamen Rider Decade, pulled off the first Rider/Sentai crossover with Samurai Sentai Shinkenger..
Cowboy BeBop at His Computer: Common in English-language media due to the lack of non-Japanese information out there. The most frequent is that any and all series and their title heroes will just be called Ultraman under the assumption that they are all the same show and character as the original, which would be like saying Superman and Superboy are the same character or referring to Captain Picard as Captain Kirk. Even This Very Wiki does it.
I Am Not Spock: Nearly every actor who has played the Ultras' human alter egos becomes more or less permanently associated with that character. A good chunk of them have pretty much embraced their roles though, notably Kohji Moritsugu (Dan Moroboshi from Ultraseven).
The big one is that after the clearing of the Chaiyo fiasco, Tsuburaya signed a deal with Mill Creek Entertainment for North American Blu-Rays and streaming of the entire franchise, starting with Ultra Q and Ultraman in October 2019.
The Ultraman X and Ultraman Ginga movies were given limited English releases in the United States in early 2017 — the first of their kind since 4Kids' infamous Tiga dub.
In 2017, the Toku Network became the first English language television channel in years to air Ultra Series, including some of the above-mentioned series, as well as Ultra Galaxy Mega Monster Battle, Neo Ultra Q, Ultraman Neos, and Ultraseven X. Ultraman Max also received a (very faithful) dub on the channel from William Winckler Productions, the same team that did the Ultraman Ginga S and Ultraman X movies.
Sadly played straight with Ultraman R/B, as Tsuburaya Productions only allowed the series to be streamed in Asia through its YouTube channel, but not in the West, as they are now finding a way to stream it outside of Asia without Crunchyroll's involvement.
Promoted Fanboy: The franchise is so popular and so old that many of the later actors were fans of the Ultra series as kids. Tatsuomi Hamada (Riku Asakura from Ultraman Geed), for example, once said that as a kid, he had always wanted to be an Ultraman, and playing the human form of Geed is a dream come true; not to mention that he has said that his favorite Ultra is Ultraman Justice.
Prop Recycling: Many suits, sets, character costumes, and props are exchanged and/or modified from series to series. In the early shows, they would often have to borrow stuff from Toho, resulting in things like Godzilla and Baragon's suits being used to present multiple monsters.
Role Reprisal: Many actors in the franchise return in later series as the same character in the event of a Crossover.
Ultraman: the Jupiter Effect, penned by Jeff Segal (who would go on to co-create Exosquad) in 1978: The plot has the alignment of all the planets in our Solar System cause major disasters around the world, causing monsters to invade. Ultraman (whose host would have been a NASA astronaut) appears to save the planet. Things would have gotten so tough that the other Ultramen from the franchise show up to lend a hand.
Ultraman: Hero From The Stars, penned by book writer Don Glut (who also wrote for The Transformers) in 1983: The plot would have involved highly evolved dinosaurs attacking the Earth after years of waiting, and a new Ultraman inhabits the body of a Earth Defense Soldier to fight back. Notably, this script featured the death of Ultra Seven during the film's climax. The screenplay was said to be pretty bad however, and it's said it ripped off too many cues from Superman: The Movie (At one point of the story, the new Ultraman even tries to impress his girlfriend with his gigantic super-powers!).
The prototype to the entire franchise was WoO, a comedic series about a comical alien named Woo and a news photographer named Joji Akita, as they battled monsters and avoided the armed forces suspicious of Woo. The series was scrapped in favor of Ultra Q, but would later be revived in 2006 as Bio Planet WoO.
The Ultras were originally going to be a race of monstrous bird-like aliens, with the original Ultraman being named Bemlar◊ (directly recycled from an unused Ultra Q villain in name and appearance). Due to fears that children wouldn't know which monster to cheer for, they gave Bemlar a more humanoid appearance. The name "Bemlar" was given to Ultraman's very first Monster of the Week while its design would be incorporated into the monster Hydra.
In the early 2010s, it was announced Tsuburaya were developing a way for the actors in the respective Ultraman series to be swapped out, so to speak, for foreign actors by distributors for easier localization ala Power Rangers. Nothing seems to have come from this however.
Previously, there had been considerations by William Winckler Productions of doing something similar with Ultraman 80 as far back as 1987, and it would have starred none other than Adam West! Not to mention that Oliver Stone, of all people, apparently considered something similar with Ultraman Gaia according to the show's head writer Chiaki Konaka.