diff --git a/testdata/dot-ref/color.dot b/testdata/dot-ref/color.dot
index 2d21d03..1452e2e 100644
--- a/testdata/dot-ref/color.dot
+++ b/testdata/dot-ref/color.dot
@@ -7,16 +7,18 @@
 digraph G {
 	edge [fontname="Helvetica",fontsize=10,labelfontname="Helvetica",labelfontsize=10];
 	node [fontname="Times",fontsize=10,shape=plaintext];
+	nodesep=0.25;
+	ranksep=0.5;
 	bgcolor=".7 .9 1";
 
 	// Pixel
-	c49 [label=<<table border="0" cellborder="1" cellspacing="0" cellpadding="2" port="p" bgcolor="#a0a0a0"><tr><td><table border="0" cellspacing="0" cellpadding="1"><tr><td align="center" balign="center"> Pixel </td></tr></table></td></tr><tr><td><table border="0" cellspacing="0" cellpadding="1"><tr><td align="left" balign="left"> - x : int </td></tr><tr><td align="left" balign="left"> - y : int </td></tr></table></td></tr></table>>, fontname="Helvetica-Bold", fontcolor="white", fontsize=14.0];
+	c49 [label=<<table title="Pixel" border="0" cellborder="1" cellspacing="0" cellpadding="2" port="p" bgcolor="#a0a0a0"><tr><td><table border="0" cellspacing="0" cellpadding="1"><tr><td align="center" balign="center"> Pixel </td></tr></table></td></tr><tr><td><table border="0" cellspacing="0" cellpadding="1"><tr><td align="left" balign="left"> - x : int </td></tr><tr><td align="left" balign="left"> - y : int </td></tr></table></td></tr></table>>, fontname="Helvetica-Bold", fontcolor="white", fontsize=14.0];
 	// Red
-	c50 [label=<<table border="0" cellborder="1" cellspacing="0" cellpadding="2" port="p" bgcolor="red"><tr><td><table border="0" cellspacing="0" cellpadding="1"><tr><td align="center" balign="center"> Red </td></tr></table></td></tr></table>>, fontname="Times", fontcolor="black", fontsize=14.0];
+	c50 [label=<<table title="Red" border="0" cellborder="1" cellspacing="0" cellpadding="2" port="p" bgcolor="red"><tr><td><table border="0" cellspacing="0" cellpadding="1"><tr><td align="center" balign="center"> Red </td></tr></table></td></tr></table>>, fontname="Times", fontcolor="black", fontsize=14.0];
 	// Green
-	c51 [label=<<table border="0" cellborder="1" cellspacing="0" cellpadding="2" port="p" bgcolor="green"><tr><td><table border="0" cellspacing="0" cellpadding="1"><tr><td align="center" balign="center"> Green </td></tr></table></td></tr></table>>, fontname="Times", fontcolor="black", fontsize=14.0];
+	c51 [label=<<table title="Green" border="0" cellborder="1" cellspacing="0" cellpadding="2" port="p" bgcolor="green"><tr><td><table border="0" cellspacing="0" cellpadding="1"><tr><td align="center" balign="center"> Green </td></tr></table></td></tr></table>>, fontname="Times", fontcolor="black", fontsize=14.0];
 	// Blue
-	c52 [label=<<table border="0" cellborder="1" cellspacing="0" cellpadding="2" port="p" bgcolor="blue"><tr><td><table border="0" cellspacing="0" cellpadding="1"><tr><td align="center" balign="center"> Blue </td></tr></table></td></tr></table>>, fontname="Times", fontcolor="black", fontsize=14.0];
+	c52 [label=<<table title="Blue" border="0" cellborder="1" cellspacing="0" cellpadding="2" port="p" bgcolor="blue"><tr><td><table border="0" cellspacing="0" cellpadding="1"><tr><td align="center" balign="center"> Blue </td></tr></table></td></tr></table>>, fontname="Times", fontcolor="black", fontsize=14.0];
 	// Pixel COMPOSED Red
 	c49:p -> c50:p [taillabel="", label="", headlabel="", fontname="Helvetica", fontcolor="black", fontsize=10.0, color="yellow", arrowhead=none, arrowtail=diamond];
 	// Pixel COMPOSED Green