Some issues:
Interaction of custom and preexisting filters - custom gets processed second, apparently, and so doesn't apply color even if it matches. For example, my gazillion wardogs are always latching and having grips broken, and I made custom filters to dim those announcements. However, the custom coloration didn't take effect unless I disabled the combat filter entirely.
More problematically, some things get displayed 3 times instead of only once - and seem to be consuming adjacent lines in the process.
Input (gamelog.txt)
The Meatshield twists the embedded (large silver dagger) around in The Goblin Thief's left foot!
The Stray Dog bites The Goblin Thief in the upper body, bruising the muscle through the ({black-crested gibbon leather cloak})!
The Stray Dog latches on firmly!
The Meatshield punches The Goblin Thief in the left hand with his right hand, bruising the bone through the ({goat leather left glove})!
The Bruiser stabs The Goblin Thief in the upper body with her ðbronze spearð, tearing the muscle and tearing the right lung through the ({black-crested gibbon leather cloak})!
The Goblin Thief is having more trouble breathing!
The ðbronze spearð has lodged firmly in the wound!
Output (dfannouncementfilter.jar v1.01)
The Meatshield twists the embedded (large silver dagger) around in The Goblin Thief's left foot!
The Stray Dog latches on firmly!
The Stray Dog latches on firmly!
The Stray Dog latches on firmly!
The Meatshield punches The Goblin Thief in the left hand with his right hand, bruising the bone through the ({goat leather left glove})!
The ðbronze spearð has lodged firmly in the wound!
The ðbronze spearð has lodged firmly in the wound!
The ðbronze spearð has lodged firmly in the wound!