fixing bugs on color pref setting, and on multiple pref setting, r=alecf@netscape.com

suite/common/pref/pref-colors.xul

@@ -54,7 +54,7 @@
     				</menupopup>
     			</menu>
     			<html:input type="hidden" id="foregroundText"
-                      pref="true" preftype="string" prefstring="browser.foreground_color"/>
+                      pref="true" preftype="color" prefstring="browser.foreground_color"/>
     		</box>
     		<box style="width: 85%" class="hspace-both">
           <html:label>&background;</html:label>
@@ -68,7 +68,7 @@
     				</menupopup>
     			</menu>
     			<html:input type="hidden" id="background"
-                      pref="true" preftype="string" prefstring="browser.background_color"/>
+                      pref="true" preftype="color" prefstring="browser.background_color"/>
     		</box>
     		<html:div class="vspace hspace-both">
 		  		<html:input type="checkbox" id="browserWFEUseWindowsColors"

suite/common/pref/pref.xul

@@ -55,10 +55,12 @@ Contributor(s): ______________________________________. -->
     <!-- content frame -->
     <html:iframe id="panelFrame" name="panelFrame" style="width:0px" flex="6"/>
     <html:script language="javascript">
-      if( window.arguments[0] ) 
+    <![CDATA[
+      if( window.arguments && window.arguments[0] ) 
         document.getElementById("panelFrame").setAttribute("src", window.arguments[0] );
       else 
         document.getElementById("panelFrame").setAttribute("src", "chrome://pref/content/pref-navigator.xul" );
+    ]]>
     </html:script>
     
     <spring style="width: 7px;"/>