widget.SetBackgroundColor(widget.GetBackgroundColor()) changes the background color

Hello,

I've been trying to make my app look nice on Ubuntu (lucid). I tried
using `.GetBackgroundColor()` for a few widgets in order to know what
the background color is. I was surprised when I got a background color
which was darker than the actual background color. I've been trying to
figure out where my mistake is. Eventually I tried:

    widget.SetBackgroundColor(widget.GetBackgroundColor())

And the widget got his background color changed to a darker one!

What's up? Why is this happening? Why am I not getting the widget's
true background color?

Thanks,
Ram.