This logo series is based on the DC Universe Lantern Corps.

Here’s an excerpt from Wikipedia explaining the color spectrum / emotion tied to each lantern:

The emotional spectrum is divided into the seven colors of the rainbow, with each color corresponding to a different emotion: rage (red), greed (orange), fear (yellow), will (green), hope (blue), compassion (indigo), and love (violet). However, it also represents the absence of color (black), which is death, and the combination of colors (white) which is life. The two emotions on the far ends of the emotional spectrum (rage and love), have a much stronger influence over their users while willpower, the center of the spectrum, can be used to overcome and maintain control over one’s emotions.