diff --git a/src/calibre/gui2/convert/comic_input.ui b/src/calibre/gui2/convert/comic_input.ui
index ca1953d6b2..2f99a1f1a0 100644
--- a/src/calibre/gui2/convert/comic_input.ui
+++ b/src/calibre/gui2/convert/comic_input.ui
@@ -7,7 +7,7 @@
     <x>0</x>
     <y>0</y>
     <width>599</width>
-    <height>398</height>
+    <height>415</height>
    </rect>
   </property>
   <property name="windowTitle">
@@ -26,15 +26,21 @@
    </item>
    <item row="3" column="1">
     <widget class="QSpinBox" name="opt_colors">
+     <property name="specialValueText">
+      <string>off</string>
+     </property>
      <property name="minimum">
-      <number>8</number>
+      <number>0</number>
      </property>
      <property name="maximum">
-      <number>32000000</number>
+      <number>256</number>
      </property>
      <property name="singleStep">
       <number>8</number>
      </property>
+     <property name="value">
+      <number>0</number>
+     </property>
     </widget>
    </item>
    <item row="5" column="0">