The main colours i think of with Portal are, well, the portal colours - Orange and Blue. The portals glow with a light, so the orange goes from a fiery orange though an glowy yellow to a yellow white. The azure blue pales through a turquoise to a white blue. Then of course, the portals can only go onto white walls, so i added that colour in to along with the metallic grey of GLaDOS herself and the Aperture laboratories.
Of course the blue, orange and white are also evident in the gels from Portal 2 - Conversion, Propulsion and Repulsion!
I wasn't sure how to use these colours as i don't normally mix the two. so ended up doing two looks!
This is my first look -
Blues - 4H, 4C and 4A
Oranges - 7F
Also blended the blues over a gunmetal grey gel eyeliner (ELF Studio gel eyeliner) and used Barrym White eyeliner for the outer flick and waterline.
Lipgloss was a peachy shimmer (cant remember what one!)
Second look i did -
Brow - 1C and 11A
Inner corner - 11A
Lid - 7D and 7I
Crease and under eye - 4E and 4H
Eyeshadows blended over gunmetal ELf Studio gel liner (i wanted to give the impression of the colours of a portal glowing over a metal background.
Barry M white eyeliner on waterliner and outer flick.
Lips - Illamasqua sheer lipgloss Provoke over LA Color Sable lip pencil.
Next Game look - Assassin's Creed!