"Mako is defined by the grey colour and the blue colour. As we go through the movie we find out that she’s defined by those colours because in her childhood we have a blue memory." "…The memory has left a stain on her hair that is blue, and she’s carrying that memory with her."
"On the other hand, Raleigh is in a colour space made up of greens, browns and amber."
"Mako and Raleigh complement each other, their colours are complementary. Their Jaeger cockpit, then, is mostly in blue and amber, their colours."
"And finally, they recuperate the heart. There’s a scene where they’re watching the robot in a service station and for the first time, the technicians uncover the heart of the robot. Mako and Raleigh are becoming vulnerable."
"And this is resolved, finally, by the reintroduction of the full red colour when they are together under the ocean."