PDF shell color highlighting inconsistent between --since and --until

[floatingatoll]

In s2-c04-log-commit-history.textile, the text block:

shell. git log -n 30 --since="1 month ago" --until=yesterday --author="schacon"

Is represented in the PDF with "--since" colored black and "--until" colored blue. The options should be highlighted consistently, either both blue (matching --author) or both black (matching -n).