Well, the header image now has a lot of blue to indicate that time of the day when most of the ingenious hacking happens - night-time. The brownish stains are meant to indicate the second most important ingredient for making good software - Caffeine; the first one being enthusiasm.
Here's the evolution of the blog header image, in reverse chronological order:
Now - T1
Now - T2
Now - T3
(Where T1 < T2 < T3)
And oh yes, I did this in Gimp. How is it?