Gray is considered neutral and dull — and is precisely for that reason one of the most interesting colors there is. It holds everything that cannot quite be named.

Yellow is the brightest and most joyful color in the spectrum — associated with the life-giving power of the sun, but equally with poison, betrayal, and cowardice. An ambivalent color in every sense.

Green is a calming, vital, and refreshing color. It is closely associated with nature, life, youth, hope, and freedom — but also, quite paradoxically, with poison, envy, and decay.

Red is an active, self-assured color — directly associated with strength, energy, passion, and, just as strongly, with danger.