Fly Line Color

[Brook Fan]

With are April fools color scheme I thought this would be a good question today.

Is there any rhyme or reason why there is different color fly line. (Yellow, Orange, Green)
Are the colors just an individuals preference or does one color work better in different situations?

[Plunker]

But I want one in this beautiful shade of Neon Pepto-Bismol...couldn't hurt could it?

[sprestwood]

Any opaque colored line will be seen as a dark line for a trout looking up at the sky. Colors will then just help the angler identify different types of line, weight, sinking, whatever. Cortland did develope clear tip and all clear fly lines for those wishing to not see the line.