Why does water create a blue and orange outline on objects within? I'm not exactly sure what is happening or what it is called, but I
Remember seeing this while lifeguarding from a high chair. When looking down at the black lines on the bottom of the pool, the black stripes would be outlined with a blue line on one side and an orange line on the other. I've also seen the same effect when looming through a telescopic lense. 

What causes these colored outlines?