diff --git a/categories.json b/categories.json
index c7a971e..bbd3f2c 100644
--- a/categories.json
+++ b/categories.json
@@ -45,7 +45,8 @@
     {
       "description": "Backpacks",
       "id": "5b5f6f6c86f774093f2ecf0b",
-      "forceCustomBackgroundColours": true
+      "forceCustomBackgroundColours": true,
+      "useSlotsBasedBackgroundColours": false
     },
     {
       "description": "Facecovers",
diff --git a/config.json b/config.json
index c3f18e5..1268f5e 100644
--- a/config.json
+++ b/config.json
@@ -75,5 +75,37 @@
       "maxValue": 100000000,
       "colour": "violet"
     }
+  ],
+  "inventorySlotBackgroundColours": [
+    {
+      "minValue": 0,
+      "maxValue": 12,
+      "colour": "orange"
+    },
+    {
+      "minValue": 13,
+      "maxValue": 19,
+      "colour": "red"
+    },
+    {
+      "minValue": 20,
+      "maxValue": 29,
+      "colour": "yellow"
+    },
+    {
+      "minValue": 30,
+      "maxValue": 34,
+      "colour": "green"
+    },
+    {
+      "minValue": 35,
+      "maxValue": 39,
+      "colour": "blue"
+    },
+    {
+      "minValue": 40,
+      "maxValue": 999,
+      "colour": "purple"
+    }
   ]
 }
\ No newline at end of file
diff --git a/src/mod.ts b/src/mod.ts
index c546b32..711ffb2 100644
--- a/src/mod.ts
+++ b/src/mod.ts
@@ -28,6 +28,7 @@ import { Money } from "@spt-aki/models/enums/Money";
 
 import config from "../config.json";
 import categoryConfig from "../categories.json";
+import { Props } from "@spt-aki/models/eft/common/tables/ITemplateItem";
 
 class EyesOfATraderMod implements IPostDBLoadMod {
   private logger: ILogger;
@@ -36,9 +37,7 @@ class EyesOfATraderMod implements IPostDBLoadMod {
   private modName = "[Eyes of a Trader]";
 
   // We want to cache all (sub)categories of the Handbook that we have enabled our mod for otherwise we'll recursively search thousands of times.
-  private enabledCategories: Category[] = [];
-  private enabledCategoriesWithoutCustomBackground: Category[] = [];
-  private enabledCategoriesWithForcedCustomBackground: Category[] = [];
+  private enabledCategories: CategoryConfig[] = [];
 
   public postDBLoad(container: DependencyContainer): void {
     this.container = container;
@@ -67,7 +66,10 @@ class EyesOfATraderMod implements IPostDBLoadMod {
       const itemProps = item._props;
       const isValidItem = itemProps.Name && itemProps.Name !== "Dog tag" && !itemProps.QuestItem;
 
-      if (this.isCategoryEnabled(handbookItem) && isValidItem) {
+      // If a categoryConfig exists for this handbook item, it means we want to display prices for this item!
+      const categoryConfig = this.enabledCategories.find(category => category.id === handbookItem.ParentId);
+
+      if (categoryConfig && isValidItem) {
         const pricing = new Pricing(
           this.getApproxTraderPrice(handbookItems, itemId),
           this.getApproxFleaPrice(itemId),
@@ -76,17 +78,18 @@ class EyesOfATraderMod implements IPostDBLoadMod {
 
         pricingMap.set(itemId, pricing);
 
-        const forceCustomBackground = this.enabledCategoriesWithForcedCustomBackground.some(category => category.Id === handbookItem.ParentId);
-
         // Display custom background colours if forced via category configs or
         // Disable custom background colours if disabled globally or per category.
         if (
-          forceCustomBackground ||
+          categoryConfig.forceCustomBackgroundColours ||
           config.useCustomBackgroundColours && 
-          !this.enabledCategoriesWithoutCustomBackground.some(category => category.Id === handbookItem.ParentId)
+          !categoryConfig.disableCustomBackgroundColours
         ) {
-          const customColour = this.getCustomBackgroundColour(pricing);
-          if (customColour && (forceCustomBackground || config.updateVioletItemBackground || itemProps.BackgroundColor !== "violet")) {
+          const customColour = categoryConfig.useSlotsBasedBackgroundColours
+            ? this.getCustomBackgroundColourBasedOnInventorySlots(itemProps)
+            : this.getCustomBackgroundColourBasedOnPrice(pricing);
+            
+          if (customColour && (categoryConfig.forceCustomBackgroundColours || config.updateVioletItemBackground || itemProps.BackgroundColor !== "violet")) {
             itemProps.BackgroundColor = customColour;
           }
         }
@@ -100,45 +103,30 @@ class EyesOfATraderMod implements IPostDBLoadMod {
 
   private cacheEnabledCategories(handbookCategories: Category[]): void {
     if (this.enabledCategories.length === 0) {
-      categoryConfig.enabledCategories.forEach(categoryConfig => {
+      categoryConfig.enabledCategories.forEach((categoryConfig: CategoryConfig) => {
         // We gotta add the parent categories first
-        const handbookCategory = handbookCategories.find(category => category.Id === categoryConfig.id);
+        this.enabledCategories.push(categoryConfig);
 
-        if (categoryConfig.disableCustomBackgroundColours) {
-          this.enabledCategoriesWithoutCustomBackground.push(handbookCategory);
-        }
-
-        // Some categories like backpacks are all purple but we generally don't want to change existing purple ones, except for these forced categories.
-        if (categoryConfig.forceCustomBackgroundColours) {
-          this.enabledCategoriesWithForcedCustomBackground.push(handbookCategory);
-        }
-
-        this.enabledCategories.push(handbookCategory)
-        
-        this.addSubCategoriesRecursively(handbookCategories, categoryConfig.id, categoryConfig.disableCustomBackgroundColours, categoryConfig.forceCustomBackgroundColours)
+        this.addSubCategoriesRecursively(handbookCategories, categoryConfig)
       });
     }
   }
 
-  private addSubCategoriesRecursively(allCategories: Category[], categoryId: string, disableCustomBackground = false, forceCustomBackground = false): void {
-    const subCategories = allCategories.filter(category => category.ParentId === categoryId);
+  private addSubCategoriesRecursively(allCategories: Category[], categoryConfig: CategoryConfig): void {
+    const subCategories = allCategories.filter(category => category.ParentId === categoryConfig.id);
     if (subCategories.length) {
-      if (disableCustomBackground) {
-        this.enabledCategoriesWithoutCustomBackground = this.enabledCategoriesWithoutCustomBackground.concat(subCategories);
-      }
-      if (forceCustomBackground) {
-        this.enabledCategoriesWithForcedCustomBackground = this.enabledCategoriesWithForcedCustomBackground.concat(subCategories);
-      }
-      this.enabledCategories = this.enabledCategories.concat(subCategories);
+      const subCategoryConfigs = subCategories.map((subCategory): CategoryConfig => ({
+        id: subCategory.Id,
+        disableCustomBackgroundColours: categoryConfig.disableCustomBackgroundColours,
+        forceCustomBackgroundColours: categoryConfig.forceCustomBackgroundColours,
+        useSlotsBasedBackgroundColours: categoryConfig.useSlotsBasedBackgroundColours
+      }));
+      this.enabledCategories = this.enabledCategories.concat(subCategoryConfigs);
 
-      subCategories.forEach(category => this.addSubCategoriesRecursively(allCategories, category.Id, disableCustomBackground));
+      subCategoryConfigs.forEach(categoryConfig => this.addSubCategoriesRecursively(allCategories, categoryConfig));
     }
   }
 
-  private isCategoryEnabled(handbookItem: HandbookItem): boolean {
-    return this.enabledCategories.some(category => category.Id === handbookItem.ParentId);
-  }
-
   private getApproxTraderPrice(handbookItems: HandbookItem[], itemId: string): number {
     const fullPrice = handbookItems.find(item => item.Id === itemId)?.Price;
     if (!fullPrice) {
@@ -158,7 +146,20 @@ class EyesOfATraderMod implements IPostDBLoadMod {
     return dynamicPrice * config.fleaPriceMultiplier;
   }
 
-  private getCustomBackgroundColour({ perSlotTraderPrice, perSlotFleaPrice, traderPrice, fleaPrice }: Pricing): string {
+  private getCustomBackgroundColourBasedOnInventorySlots({ Grids }: Props): string {
+    const totalSlots = Grids.reduce((totalSlots, grid) => {
+      const horizontal = grid._props.cellsH;
+      const vertical = grid._props.cellsV;
+      const slots = horizontal * vertical;
+
+      return totalSlots += slots;
+    }, 0);
+
+    const colourConfig = config.inventorySlotBackgroundColours.find(({ minValue, maxValue }) => totalSlots >= minValue && totalSlots <= maxValue);
+    return colourConfig?.colour;
+  }
+
+  private getCustomBackgroundColourBasedOnPrice({ perSlotTraderPrice, perSlotFleaPrice, traderPrice, fleaPrice }: Pricing): string {
     const { usePerSlotPricingForBackgrounds, useFleaPricesForBackground, fleaValueBackgroundColours, traderValueBackgroundColours, autoUseFleaPricing } = config;
     const overrideWithFleaPrice = autoUseFleaPricing.enabled && (perSlotFleaPrice / perSlotTraderPrice) > autoUseFleaPricing.fleaToTraderValueThresholdRatio;
     const useFleaPrices = useFleaPricesForBackground || overrideWithFleaPrice;
@@ -215,4 +216,12 @@ class Pricing {
   }
 }
 
+interface CategoryConfig {
+  id: string;
+  description?: string;
+  disableCustomBackgroundColours?: boolean;
+  forceCustomBackgroundColours?: boolean;
+  useSlotsBasedBackgroundColours?: boolean;
+}
+
 module.exports = { mod: new EyesOfATraderMod() };