Color: Changes the color of sunlight.
Ambient: Changes the color of natural lighting. This can be used to express day, morning, evening, or night.
Color changes the the color and level of lighting in direct sunlight.
Ambient changes the color and level of lighting in the shade and direct sunlight.
This means that:
Shade = Ambient
Direct Sunlight = Ambient + Color
For some reason the Slice tool makes me crash. Is there any other way to get a hemisphere?
I use clip to to cut stuff. To cut a hemisphere I think you have to go a bit above, or a bit below the center line. It always seems to crash if you don't. Also I suggest not editing spheres too much. They glitch alot.