I use blue. Seem to be very bright in early morning/late afternoon. Didn't help me find the arrow last year in the daylight, and don't remember if I could see the nock in the air, but didn't really need to with the shot I had. Wishing I had bought another color to compare. I have used orange lumenocks tho, and I think they were easy to see.
On a side note, I have one that must be wearing out a little. Sometimes when I nock my arrow on the string, it turns on.
Anyone color blind that uses these? I am red/green color blind so curious if they even would show up at all??