Continuity mistake: When talking to Ral, Riker takes a sip of his drink, sets the glass down, and clasps his hands. A second later, he repeats clasping his hands.
Other mistake: While Riker looks over Data's shoulder, the make up on Data's eyebrows is incomplete. The left is lighter, the right is darker.
Other mistake: When Picard walks into the brig to talk to Q, something falls in the doorway and Picard almost kicks it with his foot. The door then closes on the item that fell. (00:11:20)
Continuity mistake: When Data goes into his laughing fit, Troi is at her regular seat, but when he stops and remarks it was a wonderful feeling, the wide shot of the crew shows her seat empty. But then, when Picard is hailed, when the moon returns to its orbit, Troi is back at her seat.
Continuity mistake: As Q approaches Picard and Riker's position while playing a trumpet, both of Q's hands are on the horn. A second later, his left hand is down by his side. Then, after he makes cigars appear in Picard and Riker's mouths, his left hand is extended as he says the first part of his lines. A second later, both hands are on his horn.
Yesterday's Enterprise - S3-E15
Continuity mistake: In the episode 'Yesterday's Enterprise' (season three, episode 15), watch the final scene with Geordi and Guinan in Ten-Forward. Although time and the universe has returned to normal, Geordi is still wearing the uniform from the alternate timeline (note the sleeve detail, and the extended neck piece).
Yesterday's Enterprise - S3-E15
Visible crew/equipment: During the scan of the temporal rift at the beginning of the episode, the tip of the microphone briefly comes into view at the top of the screen above Captain Picard's head when Data says, "Nothing I have seen before." [Not visible in the remastered Blu-ray version].
Yesterday's Enterprise - S3-E15
Other mistake: The Klingons ordering the Enterprise to prepare for boarding parties doesn't make sense. La Forge had announced only moments earlier that the Enterprise was on the verge of a warp core breach. The Klingons' ship's sensors should have been able to detect the Enterprise's impending destruction.
Yesterday's Enterprise - S3-E15
Revealing mistake: When Tasha and Castillo walk up to the bar in Ten Forward, Whoopi Goldberg can be seen standing outside the door waiting for her cue to walk in the room.
Other mistake: One of the physical appearances Lal considers adopting is an Andorian female with green skin. In the Trek universe, Andorians invariably have blue skin (the Aenar are a variant of the Andorian race but are depicted with bluish-white skin, still not green). And while other humanoid races have been portrayed with different skin tones, there are some races that have only one skin hue. (ie, Andorians are always blue, Orions are always green, Ferengi are always light orange.) It is highly unlikely she or Data designed it with different skin as Data wants her to fit in, and Troi makes no mention of it.
Visible crew/equipment: While Troi tells Riker about the Captain's grueling negotiations between the Gemarians and Dachlyds, when Picard joins them on the bridge, there are three visible T-marks taped to the floor. (00:01:50)
Continuity mistake: While Tam is talking to Deanna and sits down, he says "You understood... at least a little, how I felt." While saying this, he places his left hand on his right leg. While still saying that same line, it cuts to an angle from beside Deanna and his left hand is suddenly between his legs.
Continuity mistake: To view their orders and mission, Data puts a drive into the Enterprise's computer while standing with Riker and Geordi. Riker is seen standing but leaning casually away from Data on Data's right, and Geordi is standing off to Data's left. It then cuts show the computer screen, and the three men are reflected in it. The reflection shows that Riker is suddenly almost leaning over Data's shoulder, and Geordi has moved to standing behind Data's left shoulder.
Revealing mistake: Just after Riker and Geordi are talking in the turbo lift, it cuts to a view from outside the ship and shows the USS Hood flying next to the USS Enterprise. As the ships draw nearer, the views of both ships overlap, and a black mat outline can be seen around the saucer section of the Hood as it passes by the Enterprise's starboard nacelle.
Continuity mistake: In the beginning of the episode, right after Data informs Picard that the USS Hood is on an intercept course, closing at high warp, Picard is shown in the back ground looking down at his arm rest. He looks up and turns his head to his right making it center with his body. It then cuts to a close up of Picard and he is looking to his left, and turns his head again to say "That's odd."
Continuity mistake: At the end of Barclay's sword fight on the holodeck, he has the hologram of captain Picard against a wall. When the angle is on the hologram, Barclay's sword is pressed into his chest. However, when the angle is on Barclay, the sword is several inches away from the hologram.
Factual error: The second piece of music played at the concert is by Brahms and not Mozart.
Chosen answer: The uniform does indeed change colour. It may be due to the need for a green screen in part, or perhaps some lighting altering our perception. That being said, it certainly looks green at the start, blue thereafter.
The show has been done in HD now and not sure if they fix this problem.
Dan23