What is the difference in the color of the light from a High Pressure sodium vapor streetlight and a Low Pressure sodium vapor streetlight?

You don’t have to get into spectrum specs here, or explain how it works.

Sodium vapor streetlights have been common since the late 1970s and became really common in the 1980s and 1990s and are still quite common today—though now being slowly replaced by Metal Halide and LED street lighting.

Sodium Vapor as I know it, are those peachy-yellow orange streetlights. But I have read that there are both high- and low-pressure versions of these bulbs.

So, every now and then, I used to see streetlights with bulbs that were far more YELLOW, and maybe less bright. When I say yellow, I mean strong yellow and far less peachy than the brighter streetlights.

So, I was wondering, if these are high and low pressure versions of Sodium Vapor——

—- And if not, I was wondering just what those lower-lighting YELLOW streetlight bulbs were,