diff --git a/src/xlsx/xlsxcolor.cpp b/src/xlsx/xlsxcolor.cpp
index 7aec0bc..2ec6439 100644
--- a/src/xlsx/xlsxcolor.cpp
+++ b/src/xlsx/xlsxcolor.cpp
@@ -77,7 +77,7 @@ bool XlsxColor::saveToXml(QXmlStreamWriter &writer, const QString &node) const
         writer.writeEmptyElement(QStringLiteral("color"));
 
     if (val.userType() == qMetaTypeId<QColor>()) {
-            writer.writeAttribute(QStringLiteral("rgb"), QStringLiteral("FF")+val.value<QColor>().name().mid(1));//remove #
+        writer.writeAttribute(QStringLiteral("rgb"), XlsxColor::toARGBString(val.value<QColor>()));
     } else if (val.userType() == QMetaType::QStringList) {
         QStringList themes = val.toStringList();
         writer.writeAttribute(QStringLiteral("theme"), themes[0]);
@@ -155,6 +155,24 @@ QDataStream &operator>>(QDataStream &s, XlsxColor &color)
     return s;
 }
 
+QColor XlsxColor::fromARGBString(const QString &c)
+{
+    Q_ASSERT(c.length() == 8);
+    QColor color;
+    color.setAlpha(c.mid(0, 2).toInt(0, 16));
+    color.setRed(c.mid(2, 2).toInt(0, 16));
+    color.setGreen(c.mid(4, 2).toInt(0, 16));
+    color.setBlue(c.mid(6, 2).toInt(0, 16));
+    return color;
+}
+
+QString XlsxColor::toARGBString(const QColor &c)
+{
+    QString color;
+    color.sprintf("%02X%02X%02X%02X", c.alpha(), c.red(), c.green(), c.blue());
+    return color;
+}
+
 #endif
 
 } // namespace QXlsx
diff --git a/src/xlsx/xlsxcolor_p.h b/src/xlsx/xlsxcolor_p.h
index a34ff22..a4081ae 100644
--- a/src/xlsx/xlsxcolor_p.h
+++ b/src/xlsx/xlsxcolor_p.h
@@ -66,6 +66,9 @@ public:
 
     operator QVariant() const;
 
+    static QColor fromARGBString(const QString &c);
+    static QString toARGBString(const QColor &c);
+
     bool saveToXml(QXmlStreamWriter &writer, const QString &node=QString()) const;
     bool loadFromXml(QXmlStreamReader &reader);
 
diff --git a/src/xlsx/xlsxstyles.cpp b/src/xlsx/xlsxstyles.cpp
index a597a58..836d0c1 100755
--- a/src/xlsx/xlsxstyles.cpp
+++ b/src/xlsx/xlsxstyles.cpp
@@ -1222,7 +1222,7 @@ bool Styles::readIndexedColors(QXmlStreamReader &reader)
         if (reader.tokenType() == QXmlStreamReader::StartElement) {
             if (reader.name() == QLatin1String("rgbColor")) {
                 QString color = reader.attributes().value(QLatin1String("rgb")).toString();
-                m_indexedColors.append(fromARGBString(color));
+                m_indexedColors.append(XlsxColor::fromARGBString(color));
             }
         }
     }
diff --git a/src/xlsx/xlsxutility.cpp b/src/xlsx/xlsxutility.cpp
index 0e6eeb2..5026739 100755
--- a/src/xlsx/xlsxutility.cpp
+++ b/src/xlsx/xlsxutility.cpp
@@ -54,16 +54,6 @@ QStringList splitPath(const QString &path)
     return QStringList()<<path.left(idx)<<path.mid(idx+1);
 }
 
-QColor fromARGBString(const QString &c)
-{
-    Q_ASSERT(c.length() == 8);
-    QColor color;
-    color.setRed(c.mid(2, 2).toInt(0, 16));
-    color.setGreen(c.mid(4, 2).toInt(0, 16));
-    color.setBlue(c.mid(6, 2).toInt(0, 16));
-    return color;
-}
-
 double datetimeToNumber(const QDateTime &dt, bool is1904)
 {
     //Note, for number 0, Excel2007 shown as 1900-1-0, which should be 1899-12-31
diff --git a/src/xlsx/xlsxutility_p.h b/src/xlsx/xlsxutility_p.h
index 26f1685..9d77d86 100755
--- a/src/xlsx/xlsxutility_p.h
+++ b/src/xlsx/xlsxutility_p.h
@@ -47,7 +47,6 @@ namespace QXlsx {
 
 XLSX_AUTOTEST_EXPORT int intPow(int x, int p);
 XLSX_AUTOTEST_EXPORT QStringList splitPath(const QString &path);
-XLSX_AUTOTEST_EXPORT QColor fromARGBString(const QString &c);
 XLSX_AUTOTEST_EXPORT double datetimeToNumber(const QDateTime &dt, bool is1904=false);
 XLSX_AUTOTEST_EXPORT QDateTime datetimeFromNumber(double num, bool is1904=false);
 
diff --git a/tests/auto/styles/tst_stylestest.cpp b/tests/auto/styles/tst_stylestest.cpp
index 5e1b57d..170e0f8 100644
--- a/tests/auto/styles/tst_stylestest.cpp
+++ b/tests/auto/styles/tst_stylestest.cpp
@@ -81,7 +81,7 @@ void StylesTest::testSolidFillBackgroundColor()
 
     QByteArray xmlData = styles.saveToXmlData();
 
-    QVERIFY(xmlData.contains("<patternFill patternType=\"solid\"><fgColor rgb=\"FFff0000\"/>"));
+    QVERIFY(xmlData.contains("<patternFill patternType=\"solid\"><fgColor rgb=\"FFFF0000\"/>"));
 }
 
 void StylesTest::testWriteBorders()
diff --git a/tests/auto/xlsxconditionalformatting/tst_conditionalformattingtest.cpp b/tests/auto/xlsxconditionalformatting/tst_conditionalformattingtest.cpp
index 21fde11..8b8e0e5 100644
--- a/tests/auto/xlsxconditionalformatting/tst_conditionalformattingtest.cpp
+++ b/tests/auto/xlsxconditionalformatting/tst_conditionalformattingtest.cpp
@@ -93,7 +93,7 @@ void ConditionalFormattingTest::testDataBarRules()
     QByteArray res = "<cfRule type=\"dataBar\" priority=\"1\">"
             "<dataBar><cfvo type=\"min\" val=\"0\"/>"
             "<cfvo type=\"max\" val=\"0\"/>"
-            "<color rgb=\"FF0000ff\"/></dataBar>"
+            "<color rgb=\"FF0000FF\"/></dataBar>"
             "</cfRule>";
     QVERIFY(buffer.buffer().contains(res));
 }