Just before Dr. Bashir leaves the Enterprise, he and Data are walking down a corridor chatting, and it is clearly seen that Dr. Bashir is wearing Starfleet Style black boots/shoes. Moments later, after he & Data part company and walk away from each other, look quickly at Dr. Bashir's shoes- they are now white.
Geordi LaForge plugs a cord into the side of Data's head before intentionally rendering Data unconscious to start his "dream". The cord is also in place when Data wakes up again. The cord disappears when he falls unconscious, but this moment is part of Data's fantasy POV, in which he would not visualize the cord.