They're LED floodlights which can do many things that traditional metal halide floodlights can't.
You can programme them to flash or pulse on or off, you can programme them to be a different static colour, you can programme them to change colour frequently, but that doesn't mean you should actually do any of these things!!!
I noticed last weekend that several of the floodlights at The Kassam Stadium appeared to be off ? Perhaps one per block of four though that might just be from where I was.
Though at the Hull game (Dec 20?) it looked like they were all working. After it had been raised whether Stadco were scraping on maintenance for the floodlights.