Comparing white to turqiouse isn`t exactly fair, they are so different. But ignoring colour issues, the "EV" turquoise gives out more total light than the LE white. The bluegreen colour is right at the human eye`s most sensitive region so it can be easier to see things by and probably appear brighter still, plus it has a much wider beam than the white, more of a flood illuminating a larger area. Trouble is, being turquoise you can`t really tell colours apart. It isn`t as monochromatic as green or red, still- if you need to see colours white is your only choice.
But the turquoise EV would be a good choice for general navigation indoors or out if you don`t mind the colour. It is a rather attreactive bluey-green shade...
kinda like the colour of this little grinning fellow....