When it's night and you look up at the world border or down on it the texture fades to almost invisible.
This was actually done in 14w28b but the tracker didn't allow it.

What I expected to happen was...:
The texture would stay the same all the time

What actually happened was...:
The texture faded when I looked down on it

Steps to Reproduce:
1. Start up a world in 14w28b
2. use /worldborder set 10 (just needs to be able to been seen doesn't really matter)
3. Look up a and down at the world border

The below images are (in order) looking down on the border , Looking at it straight and Looking up at it.