Low-pressure sodium lights are almost single-wavelength amber. They have a negative color rendering index, while incandescents and sunlight are 100, and most wh

Low-pressure sodium lights are almost single-wavelength amber. They have a negative color rendering index, while incandescents and sunlight are 100, and most white LEDs are around 70. LEDs can be had in the high 90s at a cost to efficiency. LED and CFL screw-in bulbs for household lighting come in a variety of color temperatures, but people usually go for 2700K-3000K. It does seem to me that people prefer warmer light for many applications. My preference for always-on outdoor lighting is none, followed by dim, warm, and shrouded.