I'd asked some time ago if anyone knew what exactly about a green painted boat (or blue too apparently) was unlucky...

Answer to my own question from http://www.answers.com/topic/unlucky-colors:
Old superstition limits choice of boat colors
Superstition has always played a large role in sailors’ lives, and no doubt always will. There is still so much about the sea, its moods, and its inhabitants that is unexplained or incomprehensible that even today it would seem foolish, if not irresponsible, to ignore the superstitious practices of our forebears. That’s why it’s considered unlucky to paint a boat blue or green, the colors of the sea. In ancient times, boats were believed to have their own souls (inherited, incidentally, from human sacrifices) and could not presume to identify themselves with the sea or any of the gods who managed its affairs. Punishment would surely follow any boat discovered to have been masquerading under false colors. Modern skeptics will no doubt scoff at such patent nonsense, but there will always be many sailors who will abide by old superstitions—if only to quell those primordial feelings of un-ease. And why not? Sailors need all the luck they can get at sea, and heeding the time-honored warnings of yore seems a reasonably convenient way to earn it— and score points for the black box.See also Black Box Theory; Figureheads; Sailing on Friday; Unlucky Names.
On a similar note, hopefully "Lucky" Dawg isn't causing ire in the depths:
"Beware of naming your boat after fearsome creatures
Just as there are unlucky colors, there are also unlucky names for boats. A vessel with a name that is too presumptuous has long been believed to attract bad luck. Presumptuous names are those that challenge the sea or the wind, especially those that boast about beating the elements and surviving their meanest blows. To call a boat Sea Conqueror or Hurricane Tamer is to tempt the fates. The gods of the wind and sea are all-powerful, and they like boat names to be suitably humble. You may recall from Greek mythology that the most important of the Titans, the vengeful Kronos, cut off his father’s genitals with a sickle and threw them into the sea. You can probably imagine how Neptune, god the sea, felt about that. Yet, in 1912, the British White Star steamship company was foolish enough to name its new Atlantic liner Titanic. Not only that, but it claimed she was unsinkable, and it launched her without a proper naming ceremony, thus depriving the gods of their share of the usual libation. Little wonder she was doomed. In the 2001 edition of The Mariner’s Book of Days, author Peter Spectre says the all-time favorite names for ships are Mary and Elizabeth. He warns that to avoid bad luck, you shouldn’t name a vessel after any of the following:
  • storms: Hurricane, Gale, Cyclone
  • fearsome creatures of the deep: Kraken, Octopus, Serpent
  • cataclysms: Quake, Eruption, Big Bang
  • evil characters: Judas, Brutus, Pilate