Factual error: The Marine Colonel in Supergirl played by Eddie McClintock spends all of his time wearing Marine Officer's Dress Blue Bravos. Marine Dress Blues are ceremonial uniforms. On rare occasions, the Charlies or Deltas (no coat) may be worn as a work uniforms (the primary exception to this rareness being recruiters). The full uniform is certainly not worn for day to day work in the field.
Continuity mistake: While Kara and Alex are on the beach the sun on the floor changes between shots.
Answer: Yes, s02e22. As Kara leaves her office, she said "go get them, Supergirl" to herself. After season 1, the show switched from a CBS production to a CW production and filming moved from L.A. to Vancouver. Flockhart isn't really a fan of traveling to shoot, and didn't want to be away from her family for so long.
Bishop73