Darkness and night-vision have long been contentious topics in MMORPGs. At one end of the argument you have the "Night-time should be Freakin' Terrifying" crew, mostly survivors of the Rivervale - Kithicor - Commonlands run or those few Barbarians who actually owned a Greater Lightstone.

At the other extreme comes Team "Mommy lets me Sleep with the Lights On".  They feel a gentle blue tint is more than enough to let you know darkness has fallen.

There seems little doubt where the good folk at Daybreak Games stand on the matter. Allow me to illustrate:

Antonica at Dawn. A little too much of the Roger Deans, perhaps, but bright and cheery with it.

Antonica at Noon. Overcast. Looks like rain. Visibility: good.

Antonica at Sunset. Air pollution index: high. Or possibly I am. 

Antonica at Midnight. Good thing my pet's made of granite. Granite's radioactive, didn't you know?

Also, isn't it lucky I'm a Conjuror? We have Infravision! Look what a difference that makes!

The sea around Antonica seems to be mildly phosphorescent. Doesn't help much, does it?

This is The Caves. It's underground. Can you tell how it's different to Antonica at night? No? Well, this is The Caves in day time!

Antonica, just before Dawn. You can tell it's just before dawn because the crickets start chirping. And it gets just light enough to find out where in the hell you are.