I am trying to make a shapeless recipe so you can dye a wool back to white wool but it is not working.

GameRegistry.addShapelessRecipe(new ItemStack(Blocks.wool, 1, 0), new Object[] {new ItemStack(Items.dye, 1, 0), new ItemStack(Blocks.wool, 1, 1)});

GameRegistry.addShapelessRecipe(new ItemStack(Blocks.wool, 1, 0), new Object[] {new ItemStack(Items.dye, 1, 0, Blocks.wool, 1, 1)});

try that as this works

 GameRegistry.addShapelessRecipe(new ItemStack(Blocks.mossy_cobblestone, 4), new Object [] {Blocks.cobblestone, Blocks.vine});

it doesn't work with an item, just with blocks