Instead of dyeing her hair for the final season Rachel Nichols (Kiera) wore a wig.
First season was "Time". Second one was "Seconds". Third one was "Minutes". And this season has "Hours" in its episodic titles.
Richard Harmon, Ian Tracy, Aleks Paunovic, Terry Chen, Alessandro Juliani and Ty Olsson have all appeared in The 100 as John Murphy, Vincent Vie, Augustus, Commander Shumway, Jacapo Sinclair and Nyko, respectively.
Michael Eklund (Robert Zorin) & Ian Tracey (Jason) also worked together on Bates Motel (2013) as Zane Morgan & Remo Wallace respectively.
The building with the white, pointed structures seen from Kellogg's office is the Vancouver Convention Centre.