diff --git a/BookingSystem/inventory.py b/BookingSystem/inventory.py
index b77d1ab..3c5d83b 100644
--- a/BookingSystem/inventory.py
+++ b/BookingSystem/inventory.py
@@ -71,6 +71,19 @@ def order_due_date_fmt(self) -> str:
             return ''
         return parser.parse(self.order_due_date).strftime('%d.%m.%Y')
 
+    @property
+    def last_seen_td_html(self) -> str:
+        if not self.last_seen:
+            return ''
+        parsed = parser.parse(self.last_seen)
+        # Show last seen within 3hrs as new (color in table)
+        within_3hrs = 'class="last-seen-new"' if parsed > datetime.now() - timedelta(hours=3) else ''
+        # 1yr = 1 school year (300 days) (color in table)
+        over_1yr = 'class="last-seen-old"' if parsed < datetime.now() - timedelta(days=300) else ''
+        inject_class = f'{within_3hrs}{over_1yr}'
+        # Construct HTML
+        return f"<td data-sort=\"{self.last_seen}\"{inject_class}>{parsed.strftime('%d.%m.%Y')}</td>"
+
     @property
     def user(self) -> dict:
         if self.borrowed_to is None:
diff --git a/BookingSystem/templates/inventar.html b/BookingSystem/templates/inventar.html
index 9b5f7cd..94f3f39 100644
--- a/BookingSystem/templates/inventar.html
+++ b/BookingSystem/templates/inventar.html
@@ -37,7 +37,7 @@ <h3>Her kan du legge til og endre inventaren. Du kan også skrive ut etiketter.<
                 <td>{{ item.id }}</td>
                 <td>{{ item.name }}</td>
                 <td>{{ item.category }}</td>
-                <td>{{ item.last_seen }}</td>
+                {{ item.last_seen_td_html | safe }}
                 <td>
                     {% if item.available %}
                         <a href="{{ url_for('app.edit_item', item_id=item.id) }}">Rediger</a>
diff --git a/BookingSystem/templates/partials/css.html b/BookingSystem/templates/partials/css.html
index 0162405..a608510 100644
--- a/BookingSystem/templates/partials/css.html
+++ b/BookingSystem/templates/partials/css.html
@@ -48,6 +48,14 @@
     color: var(--form-element-color);
   }
 
+  .last-seen-new {
+    color: var(--form-element-valid-active-border-color);
+  }
+
+  .last-seen-old {
+    color: var(--form-element-invalid-active-border-color);
+  }
+
   /* Use the same max-width as body main */
   @media (min-width: 1200px) {
     #bulletin-contents {