     ''').serialize()
   expectedSerialization = '''<document><block
       precedence="1"
-      color="blue"
+      color="purple"
       socketLevel="0"
       classes="ul">&amp;lt;ul&amp;gt;<indent
       prefix="  "
       classes="ul">
     <block
       precedence="1"
-      color="pink"
+      color="purple"
       socketLevel="0"
       classes="li">&amp;lt;li&amp;gt;<indent
       prefix="  "
       classes="li"><block
       precedence="1"
-      color="cyan"
+      color="lightgreen"
       socketLevel="0"
       classes="#text"><socket
       precedence="0"

    &amp;lt;/head&amp;gt;</block>
    <block
      precedence="1"
      color="return"
      socketLevel="0"
      classes="body">&amp;lt;body&amp;gt;<indent
      prefix="  "
      classes="body">
    <block
      precedence="1"
      color="cyan"
      socketLevel="0"
      classes="#text"><socket
      precedence="0"

    ''').serialize()
  expectedSerialization = '''<document><block
      precedence="1"
      color="lightblue"
      socketLevel="0"
      classes="html">&amp;lt;html&amp;gt;<indent
      prefix="  "
      classes="html">
    <block
      precedence="1"
      color="purple"
      socketLevel="0"
      classes="p">&amp;lt;p&amp;gt;<indent
      prefix="  "
      classes="p">
    <block
      precedence="1"
      color="lightgreen"
      socketLevel="0"
      classes="#text"><socket
      precedence="0"
