Just my $.02 Installing as white will give you more light to see at night, mine were bright enough I had to turn them off in traffic. You could see people holding their hand up to block the light from the side view mirror. You end up with just a bigger white blob coming down the road. The yellow give you the fog advantage as well as adding a conspictus factor. For instance, big white dot headlight, two yellow dots on forks has been noticed sooner then on big white dot. I had the cars pulling out into the passing lane consistently one day, could not understand why this day was so different, then noticed my yellows were off, put on and much less pull outs. You see their turn signals light up and then go out when they "see" you, then pull out when your gone. This is what I was going for. YMMV