diff -urB qt-everywhere-opensource-src-4.7.4.orig//src/gui/text/qtextdocument.cpp qt-everywhere-opensource-src-4.7.4/src/gui/text/qtextdocument.cpp
--- qt-everywhere-opensource-src-4.7.4.orig//src/gui/text/qtextdocument.cpp	2011-09-12 10:49:28.000000000 +0400
+++ qt-everywhere-opensource-src-4.7.4/src/gui/text/qtextdocument.cpp	2011-09-25 17:41:24.000000000 +0400
@@ -2225,7 +2225,15 @@
     if (format.background() != defaultCharFormat.background()
         && format.background().style() == Qt::SolidPattern) {
         html += QLatin1String(" background-color:");
-        html += format.background().color().name();
+        if (format.background().color().alpha() == 255)
+            html += format.background().color().name();
+        else if (format.background().color().alpha())
+            html += "rgba(" + QString::number(format.background().color().red()) + "," +
+                              QString::number(format.background().color().green()) + "," +
+                              QString::number(format.background().color().blue()) + "," +
+                              QString::number(format.background().color().alpha()) + ")";
+        else
+            html += "transparent";
         html += QLatin1Char(';');
         attributesEmitted = true;
     }