Could also be a QC label, added after final visual or electrical testing. Often has a small stamp on it or the initials of the inspector. Colour is often determined by which shift or line did it. I used them as well, to provide traceability to a machine in case of a callback for poor production.
I was refering to if you have people outside it may cause irritable glare. My eyes are very sensitive to light and the glare from my 250w MH walpack bothers me, so that's why I brought this up. If you look at the lume at the angle where the glass of the lume bends, it is glarey.
But 400w of anything is kinda bright for a yard