Just as there’s an Amber Alert for missing kids and Silver Alerts for missing elderly, pirates have their own alert system
The problem was naming the thing.
The Jolly Roger has only two colors on it: White and Black.
And let’s face it: announcing White and Black Alerts is a bit awkward in the 21st Century.
Pirates like Gold, but people might mistake a Gold Alert as some kind of warning to sell their Gold.
Pirates also like Silver, but there’s already a Silver Alert for the elderly.
Which isn’t a problem if the missing pirate happens to be elderly.