Ohhh, that's what those are for! Saw them all over the shop and had no clue what they're for. A friend of mine has been accumulating a huge school of simulans (Green Neons) for awhile now and they are too cool for school. I thought they would be boring because there's no red, BUT the blue stripe is sorta tealish and like LED-bright. It is jaw-dropping. Nice, tight schoolers too.