When you use Bone Meal as a dye on Wool, you just get Wool in return. Also, once Wool has been dyed another color, it cannot be dyed white again.
What's the point of using Bone Meal if it doesn't change anything?
Best Answer
Bone Meal is also used to make Light Blue and Pink Dye (when mixed with a Lapis Lazuli and a Rose Red respectively). As to why you would need to make white wool, I don't know.
OptiFine has, among many other improvements, a clear water option (under Video Options -> Details). This is a pure client modification and works just as fine in SMP. (Note that this is not compatible with MCPatcher, which is however not needed since OptiFine also includes HD texture support).
The file won't regenerate unless you update Minecraft, and needs to be removed only once for a given version. (If Minecraft has an update and you pick "yes" when it asks if you want to update, it'll reinstall a fresh, new copy of the game, with a brand-new META-INF file and none of your mods.)
The META-INF file is a code signing file. Removing it is necessary if you mod Minecraft because the game will no longer match the code signature, and therefore won't start. Removing it prevents the game from checking if it matches, so then it runs fine.
Best Answer
Bone Meal is also used to make Light Blue and Pink Dye (when mixed with a Lapis Lazuli and a Rose Red respectively). As to why you would need to make white wool, I don't know.