Warning: SPOILERS for Star Trek: Lower Decks season 5, episode 7, "Fully Dilated"

Lower Decks season 5, episode 7, "Fully Dilated," the Cerritos sends Lts. Beckett Mariner (Tawny Newsome), D'Vana Tendi (Noël Wells), and T'Lyn (Gabrielle Ruiz) to retrieve technology that an alternate universe USS Enterprise-D left on Dilmer III.

While on the planet, Mariner, Tendi, and T'Lyn find the purple disembodied head of Lt. Commander Data (Brent Spiner) among debris from a shuttlecraft crash. This version of Data comes from a universe that appears to be similar to Star Trek's Prime Universe, except that everything is purple. Before Data returns to his own universe, he talks with Captain Carol Freeman (Dawnn Lewis). Upon learning that the Prime Universe Enterprise-D is "just neutral gray," Data responds that "that seems like a missed opportunity when purple is an option."

Why The USS Enterprise & Starfleet Ships Are Gray In Star Trek

In Our Universe, Gray Starships Just Make The Most Sense

While Star Trek has not provided any specific explanation as to why Starfleet's ships are gray, it likely has a lot to do with practicality. Star Trek creator Gene Roddenberry had served in the Army Air Forces during World War II and developed a fascination for the aircraft carrier named Enterprise. This battleship inspired the name of Star Trek's iconic ship, and the grayish coloring was likely also inspired by military ships. Within the Star Trek universe, Starfleet ships are constructed mostly of metal, and keeping the original coloring is much less work than maintaining a colorful paint job.

In Star Trek: The Original Series, Captain James T. Kirk's (William Shatner) USS Enterprise often looked light gray or almost white. This helped the ship stand out against the black backdrop of space. The grays and whites of Starfleet ships also make the ships feel more realistic because of their similarities to modern battleships and airplanes. Once Starfleet began making their ships gray, they likely chose to stick with the color scheme for the sake of consistency. While individuals could presumably paint their own ships however they liked, Starfleet would want to keep a uniform look for their fleet.

Star Trek’s Alien Ships Are Different Colors Besides Gray

Romulans, Klingons, & Vulcans Have Have Ships Of Various Colors

Not all Star Trek ships are gray, however, and different alien species often use different color schemes for their ships. Although no real explanation has been provided for why different aliens have different colored ships, there are several reasons why this might be the case. It's possible the materials and alloys used to produce Klingon and Romulan ships, for example, have more of a greenish tint than the materials Starfleet uses. The various colors of ships also make it easier to distinguish different species and keep track of ships during battle sequences.

Most of the starships featured in Star Trek's Prime Universe come in colors that could be naturally occurring in the metallic materials used to construct the ships. Metals and other materials could come in gray, black, green, or red, for example, depending on what planet they originated from. Plus, different alien cultures likely associate colors with certain qualities. Perhaps Romulan ships are green because their blood is green and they associate the color with violence and war. Romulans have also been known to paint giant birds on the underside of their Birds-Of-Prey, presumably as an intimidation tactic.

Lower Decks Purple Universe Raises Lots Of Questions

Is Everything In That Universe Purple Or Just Earth-Related Things?

No one from Star Trek: Lower Decks actually visits the Purple Universe, but images of the purple USS Enterprise can be seen on Captain Freeman's datapad. Data himself is completely purple, which suggests that the humans of his universe are also purple. This raises some interesting questions. If humans are varying shades of purple, it has profound implications for alien species like the blue Andorians and the green Orions. Perhaps it is only Earth and humanity that are purple, and every other species remains the same color they are in the Prime Universe.

Data does not seem surprised by the existence of colors other than purple, suggesting that other colors exist in his world. This s the idea that everything (or almost everything) on Earth is purple, including the materials used to craft starships, but that other planets and civilizations have more colors. Whatever the case, Star Trek: Lower Decks season 5 offers a fascinating new take on Star Trek's multiverse and it remains to be seen whether the show will check back in with Purple Data and his purple universe.