fix: name water-only sauces properly and stop the plate NPE

src/main/java/net/tfminecraft/cooking/cache/CategoryDictionary.java

@@ -25,6 +25,8 @@ public static String getName(String key) {
     }
 
     public static String getSauceItemPath(String colour, int index) {
+        // Uncoloured names (water-only mixes, or older "000000Mixed Sauce" items) have no hex to read.
+        if (colour == null) return ItemCache.liquidFallback;
         int rTotal = 0, gTotal = 0, bTotal = 0, count = 0;
         String hex = colour.replace("#", "");
         if (hex.equalsIgnoreCase("000000")) return ItemCache.liquidFallback;

src/main/java/net/tfminecraft/cooking/cooking/CookingReference.java

@@ -310,7 +310,7 @@ protected String applyNameTemplate(FoodItem product, String colour, String typeL
         if (fillers.isEmpty()) {
             fillers = "Mixed ";
         }
-        displayName = displayName.replace("{colour}", colour == null ? "" : colour);
+        displayName = displayName.replace("{colour}", DisplayUtils.getNameColour(colour));
         displayName = displayName.replace("{prefixes}", NameComposer.formatPrefixes(product));
         displayName = displayName.replace("{fillers}", fillers);
         displayName = displayName.replace("{ingredients}", getName(typeLabel));

src/main/java/net/tfminecraft/cooking/cooking/SauceReference.java

@@ -20,6 +20,8 @@
 
 import org.bukkit.inventory.meta.ItemMeta;
 
+import org.bukkit.persistence.PersistentDataType;
+
 
 
 import net.tfminecraft.tlibs.TLibs;
@@ -58,6 +60,8 @@
 
 import net.tfminecraft.cooking.utils.ItemBuilder;
 
+import net.tfminecraft.cooking.utils.Keys;
+
 import net.tfminecraft.cooking.utils.StationAddonRules;
 
 import net.tfminecraft.interactiblefurniture.events.FurnitureInteractEvent;
@@ -306,11 +310,14 @@ public void scoop(Player p, ItemStack ladle) {
 
 
 
-        String displayName = applyNameTemplate(sauce, DisplayUtils.getMergedColour(colours), "Sauce");
+        String colour = DisplayUtils.getMergedColour(colours);
+        String displayName = applyNameTemplate(sauce, colour, "Sauce");
 
         ItemMeta m = output.getItemMeta();
 
         m.setDisplayName(StringFormatter.formatHex(displayName));
+        // The name can't carry every colour (Paper stores #ffffff as named white), so keep it here too.
+        m.getPersistentDataContainer().set(Keys.SAUCE_COLOUR, PersistentDataType.STRING, colour);
 
         output.setItemMeta(m);
 

src/main/java/net/tfminecraft/cooking/manager/PlateManager.java

@@ -181,12 +181,19 @@ public void addSauce(Player p, Furniture f, FoodItem sauce, ItemStack base) {
 
         if (f.getType() == null || f.getType().getSlot("sauce") == null) return;
         if(f.hasActiveSlot("sauce")) return;
-        String saucePath = CategoryDictionary.getSauceItemPath(
-            StringFormatter.extractHexColor(base.getItemMeta().getDisplayName()), 1);
+        ItemMeta baseMeta = base.getItemMeta();
+        String saucePath = CategoryDictionary.getSauceItemPath(sauceColour(
+            baseMeta.getPersistentDataContainer().get(Keys.SAUCE_COLOUR, PersistentDataType.STRING),
+            baseMeta.getDisplayName()), 1);
         f.getOrCreatePlacedSlot("sauce").forceModel(TLibs.getItemAPI().getCreator().getItemFromPath(saucePath));
         f.getLoc().getWorld().playSound(f.getLoc(), Sound.ITEM_BUCKET_FILL, 1f, 1f); //TODO SOUND
     }
 
+    /** Sauce colour stored at scoop time; ladles scooped before it existed fall back to the name's colour. */
+    static String sauceColour(String stored, String displayName) {
+        return stored != null ? stored : StringFormatter.extractHexColor(displayName);
+    }
+
     public void addSoup(Player p, Furniture f, FoodItem soup, ItemStack base) {
         p.getInventory().setItemInMainHand(
             TLibs.getItemAPI().getCreator().getItemFromPath(ItemCache.ladle)

src/main/java/net/tfminecraft/cooking/utils/DisplayUtils.java

@@ -56,9 +56,10 @@ public static String getDisplayString(String name, double foodMultiplier, double
         return name + " §8(" + extra.toString() + "§8)";
     }
 
+    /** Average of the stored {@code rrggbb} colours, always as {@code #rrggbb}. */
     public static String getMergedColour(List<String> colours) {
-        if (colours.size() == 0) return "000000";
-        if (colours.size() == 1) return colours.get(0);
+        if (colours.size() == 0) return "#000000";
+        if (colours.size() == 1) return "#" + colours.get(0).replace("#", "");
 
         int r = 0, g = 0, b = 0;
 
@@ -78,6 +79,15 @@ public static String getMergedColour(List<String> colours) {
         return String.format("#%02x%02x%02x", r, g, b);
     }
 
+    /**
+     * Colour code for a sauce or soup name. A mix of only uncoloured liquids (water) merges to
+     * {@code #000000}, which would print black, so it uses white instead.
+     */
+    public static String getNameColour(String mergedColour) {
+        if (mergedColour == null || mergedColour.replace("#", "").equalsIgnoreCase("000000")) return "&f";
+        return mergedColour;
+    }
+
     public static String getSauceStatString(double food, double nutrition) {
         StringBuilder sb = new StringBuilder();
 

src/main/java/net/tfminecraft/cooking/utils/Keys.java

@@ -41,6 +41,9 @@ public class Keys {
             new NamespacedKey(Cooking.plugin, "sauce");
     public static final NamespacedKey SAUCE_NAME =
             new NamespacedKey(Cooking.plugin, "sauce_name");
+    /** Merged {@code #rrggbb} colour of a scooped sauce; plates pick their sauce visual from it. */
+    public static final NamespacedKey SAUCE_COLOUR =
+            new NamespacedKey(Cooking.plugin, "sauce_colour");
     public static final NamespacedKey CARVE_SEQUENCE =
             new NamespacedKey(Cooking.plugin, "carve_sequence");
     public static final NamespacedKey CARVE_NEXT_INDEX =

src/test/java/net/tfminecraft/cooking/cache/SauceColourTest.java

@@ -0,0 +1,74 @@
+package net.tfminecraft.cooking.cache;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
+
+import java.util.HashMap;
+import java.util.List;
+
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import net.tfminecraft.cooking.utils.DisplayUtils;
+import net.tfminecraft.tlibs.objects.api.subapi.StringFormatter;
+
+class SauceColourTest {
+    private static final String WATER = "ia.test:water";
+    private static final String MILK_PLATED = "ia.test:milk_plated";
+
+    private String previousFallback;
+    private HashMap<String, String> previousDict;
+
+    @BeforeEach
+    void setUp() {
+        previousFallback = ItemCache.liquidFallback;
+        previousDict = CategoryDictionary.sauceDict;
+        ItemCache.liquidFallback = WATER;
+        CategoryDictionary.sauceDict = new HashMap<>();
+        CategoryDictionary.sauceDict.put("ffffff", "ia.test:milk|" + MILK_PLATED);
+    }
+
+    @AfterEach
+    void tearDown() {
+        ItemCache.liquidFallback = previousFallback;
+        CategoryDictionary.sauceDict = previousDict;
+    }
+
+    @Test
+    void mergedColourAlwaysHasAHash() {
+        assertEquals("#000000", DisplayUtils.getMergedColour(List.of()));
+        assertEquals("#000000", DisplayUtils.getMergedColour(List.of("000000")));
+        assertEquals("#ffffff", DisplayUtils.getMergedColour(List.of("ffffff")));
+        assertEquals("#abcdef", DisplayUtils.getMergedColour(List.of("#abcdef")));
+        assertEquals("#185d15", DisplayUtils.getMergedColour(List.of("000000", "30ba2b")));
+    }
+
+    @Test
+    void uncolouredMixesAreNamedWhite() {
+        assertEquals("&f", DisplayUtils.getNameColour("#000000"));
+        assertEquals("&f", DisplayUtils.getNameColour(null));
+        assertEquals("#185d15", DisplayUtils.getNameColour("#185d15"));
+    }
+
+    @Test
+    void waterOnlySauceNameShowsTheWaterVisual() {
+        String name = StringFormatter.formatHex(
+                DisplayUtils.getNameColour(DisplayUtils.getMergedColour(List.of("000000"))) + "Mixed Sauce");
+
+        assertEquals("§fMixed Sauce", name);
+        assertNull(StringFormatter.extractHexColor(name));
+        assertEquals(WATER, CategoryDictionary.getSauceItemPath(StringFormatter.extractHexColor(name), 1));
+    }
+
+    @Test
+    void olderUncolouredSauceNameShowsTheWaterVisual() {
+        assertEquals(WATER, CategoryDictionary.getSauceItemPath(StringFormatter.extractHexColor("000000Mixed Sauce"), 1));
+    }
+
+    @Test
+    void milkOnlySauceColourShowsTheMilkVisual() {
+        // Scooping stores this merged colour on the ladle; the name alone can't carry it (Paper keeps #ffffff as named white).
+        assertEquals(MILK_PLATED, CategoryDictionary.getSauceItemPath(DisplayUtils.getMergedColour(List.of("ffffff")), 1));
+    }
+}

src/test/java/net/tfminecraft/cooking/manager/PlateManagerTest.java

@@ -1,7 +1,9 @@
 package net.tfminecraft.cooking.manager;
 
 import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNull;
 import static org.junit.jupiter.api.Assertions.assertSame;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
@@ -14,6 +16,7 @@
 
 import net.tfminecraft.interactiblefurniture.furniture.Furniture;
 import net.tfminecraft.interactiblefurniture.furniture.PlacedSlot;
+import net.tfminecraft.tlibs.objects.api.subapi.StringFormatter;
 
 class PlateManagerTest {
 
@@ -175,6 +178,17 @@ public boolean hasItemMeta() {
         assertFalse(plate.hasActiveSlot("sauce"));
     }
 
+    @Test
+    void storedSauceColourWinsOverTheName() {
+        assertEquals("#ffffff", PlateManager.sauceColour("#ffffff", "§fMixed Sauce"));
+    }
+
+    @Test
+    void ladlesWithoutAStoredColourFallBackToTheName() {
+        assertEquals("#185d15", PlateManager.sauceColour(null, StringFormatter.formatHex("#185d15Basil Sauce")));
+        assertNull(PlateManager.sauceColour(null, "000000Mixed Sauce"));
+    }
+
     @Test
     void displaySlotsDoNotCountAsFood() {
         Furniture plate = plateWithSauceVisual();