I am sure that there is a setting to make the lighting more amenable to viewing changes made, but I don't know what they would be. I checked the time of day, it is at 10:00 AM.

Any suggestions?

You can change the lighting by pressing the A key.

EDIT: The Render Window has to be the active window when pressing A for it to work. So just click on the Render Window and press A to change the lighting. The lighting will also change in any Preview windows.

Thank you... That's just so intuitive...

Is there a way to adjust the lighting? I mean, other than 'too dark' or 'too bright'?

Amethyst Deceiver made http://skyrim.nexusmods.com/mods/17018 to help see NPCs properly when designing them.

I can recommend using this when creating characters. I've found it to be much easier than doing it with CK.

Ahh... Amethyst Deceiver... She's a tricky one. And I'll probably try her mod, but for now I just want to know how to adjust the CK's lights...

If you select the cell you want to edit in the cell list in th Cell View window, right click on it, and select Edit from the menu, the light settings for that cell are in the tabs in the edit dialogue that comes up. They are relatively complex and are worthy of their own tutorial. There might be some out there, but I have never found a good one. The tutorial on CreationKit.com is pretty basic. Don't be surprised if what you see in the game looks nothing like what you saw in the CK.

And Amethyst Deceiver's Photobooth mod is a big help on creating NPCs.