What is Dark Blue Voices, Bright Red Voices?

An excerpt from one of my original songs, called "Cyanide," written August 2013:

"These dark blue voices
Calling softly
Take me away

These bright red voices
Screaming at me
Listen to me now, don't wanna hear you..."

There are many voices in my head, in your head, in our heads. Some are yellow, smiling, enthusiastic. Some are grey, dull, drab. Some are fuchsia, lime green, gold, lilac. All speak at different volumes, send different messages, have different personalities. Dark blue voices are slow. They creep though your brain, whispering sweet nothings to lure you into their grasp. Some call dark blue voices depression. I call them fair-weather friends. Bright red voices are loud. Fast. Screaming through your veins, flying in and out of your eyes, lighting fires, igniting barely-containable explosions. Some call bright red voices mania. I call them the high at the top of a roller coaster before the drop. Dark blue voices, bright red voices. Some call this bipolar. I call it my life.