The roof was in shadow, and the windows, partially glazed with coloured glass and partially unglazed, admitted a tempered light.
There are no more uses of "tempered" in the book.
Show samples from other sources
If you had only given me some hint, if you had only broken your word with me a couple of times, if you had been bad-tempered or impatient with me—if you had been a lesser man, maybe I could have taken what I saw you doing.
Harper Lee -- Go Set a Watchman
For the rest of the day, I’m short-tempered and distracted.