» Thu Feb 04, 2010 4:07 pm
You have to edit the texture in a program, like Gimp or many others. (many of which are free.)
Lot of details and links http://www.zyworld.com/redwoodtreesprite/FreeGraphicPrograms.htm and more links to tutorials http://www.gamesas.com/index.php?/topic/24-comprehensive-tutorial-and-useful-link-list/