The underlying libraries WTF is built upon use colour strings to define colours, so WTF does too.

But this is a cool idea. Issue #546 has been opened for this.

Yeah, this makes it unusable on my terminal because I have a custom color scheme.

The background of the borders matches my terminal while I can't get the background of the widgets to match because of this.

EDIT: Hah, specifying "transparent" makes it work