This is sort of on and off topic.  Since we're dealing with reality and luxrender; lighting seems to always be the key.  I've looked all over for various light temperatures and have not found anything concise on it.  Recently I acquired a book on nude and portrait photography by Helmut Newton(long time playboy photo) and he gave a list he uses as light temperatures for his work.  For natural light they are as follows:

Sunrise, sunset 3200 K
High noon 5000–5400 K
Open sky 5500–6500 K
Overcast sky 6000–7500 K
Open shade 7000–8000 K
Partly cloudy sky 8000–10,000 K
Blue sky 9000–12,000 K

And temps for his most commonly used artificial light temps:

Match 1700–1800 K
Candle 1850–1930 K
Household bulbs 2500–2900 K
Quartz/Halogen bulbs 2800–3400 K

 

Hope this is able to help someone.  I'm going to be experimenting a bit more to see what kind of effects I can achieve.