What I expected to happen was:
Horizon and sky brightness/color to only be affected by the in-game time, just like the behavior in previous official Minecraft releases (1.6.2 , 1.6.4).

What actually happened was:
The brightness/color of the horizon and sky was affected accordingly to the light level of the player's position.

Steps to Reproduce:

• Find a place where you can have clear view of the horizon.
• Build a sunshade there.
• Look at the horizon while directly under the sky.
• Then go under the sunshade and observe how the horizon becomes darker.

Note to mods: This is not the same bug report as MC-1380.

The first and the second screenshot show the difference between versions 13w39b and 1.6.4 .