It's just a small power-efficient lamp post with a built-in combinator for an easy color selection (opens on click).
Can be used for decoration, as a simple marker for specific places, circuit network signal indicator, or a single-slot constant combinator.
General glow parameters for these are configurable via mod options. There's also an option to add extra colors for all lamps to use.
Mod settings (startup tab):
Add extra color signals
Adds extra row of lamp color "virtual signals" to pick from, which can be used with regular lamps as well.
Lamp Post glow radius
Radius for lamp post glow, when any signal is set on it. Default: 6. 0 - disabled.
Lamp Post glow intensity
Glow intensity value for lamp posts, in 0 (no light) - 1.0 (bright) range. Default: 0.9.
Lamp Post color intensity
Lamp post glow color intensity, from 0 (white) to 1.0 (full color). Does not affect color of the lamp itself. Default: 0.135.
When pasing these lamps from blueprints, note that these will contain missing "Smart Lamp Data" items, which are settings for these lamps, and will be auto-created when lamp is built - no need to worry about those.