Blue

Wavelength 440–490 nm
Frequency 680–610 THz
Hex triplet #0000FF
RGBB (r, g, b) (0, 0, 255)

'the color of heaven and the abyss, the sky and the sea, the color of sobriety and temperance, but also the color of the imagination...' Alexander Theroux

An amazing weekend spent dunking fabric in stinky brown water and hanging it out to watch it turn bright blue still baffles me...