Greek sail decoration

[Paullus]

I was wondering if anyone can tell me if the Greeks ever put logos, if you will, on their sails? Ala the bulls, lambdas, and sunbursts on the sails of the ships in "Troy". Not particularly certain if it is even a historical fact, but it would strike me that a painted design on the canvas might be useful in identifying ships and fleets in open waters, when you would be using sails.

Something like this, although it looks hideously out of place and it is a game screenshot, but it does portray what I am getting at:
http://guidesmedia.ign.com/guides/15972 ... rireme.JPG
Sorry about the small size.

In particular I am curious since a friend asked me about it in regard to an artistic interpretation. Thanks in advance!