Test

import org.bukkit.Color;
import org.bukkit.FireworkEffect;
import org.bukkit.Material;
import org.bukkit.inventory.ItemStack;
import org.bukkit.inventory.meta.FireworkMeta;

public final class Test {
  public static ItemStack getItemStack() {
    ItemStack item = new ItemStack(Material.FIREWORK);
    FireworkMeta meta = (FireworkMeta) item.getItemMeta();
    meta.setPower(1);
    FireworkEffect.Builder effect1 = FireworkEffect.builder();
    effect1.with(FireworkEffect.Type.CREEPER);
    effect1.withColor(Color.fromBGR(2896307));
    effect1.withFade(Color.fromBGR(1724731));
    meta.addEffect(effect1.build());
    meta.setDisplayName("Angry Creeper");
    item.setItemMeta(meta);
    return item;
  }
}