diff --git a/src/Gui/ViewProviderLink.cpp b/src/Gui/ViewProviderLink.cpp
index 1090f66b13..a2cad7a67f 100644
--- a/src/Gui/ViewProviderLink.cpp
+++ b/src/Gui/ViewProviderLink.cpp
@@ -1002,7 +1002,7 @@ void LinkView::setMaterial(int index, const App::Material *material) {
             return;
         }
         App::Color c = material->diffuseColor;
-        c.a = material->transparency;
+        c.setTransparency(material->transparency);
         pcLinkRoot->setColorOverride(c);
         for(int i=0;i<getSize();++i)
             setMaterial(i,nullptr);
@@ -1015,7 +1015,7 @@ void LinkView::setMaterial(int index, const App::Material *material) {
             return;
         }
         App::Color c = material->diffuseColor;
-        c.a = material->transparency;
+        c.setTransparency(material->transparency);
         info.pcRoot->setColorOverride(c);
     }
 }
@@ -3074,7 +3074,7 @@ std::map<std::string, App::Color> ViewProviderLink::getElementColors(const char
     if(wildcard == "Face" || wildcard == "Face*" || wildcard.empty()) {
         if(wildcard.size()==4 || OverrideMaterial.getValue()) {
             App::Color c = ShapeMaterial.getValue().diffuseColor;
-            c.a = ShapeMaterial.getValue().transparency;
+            c.setTransparency(ShapeMaterial.getValue().transparency);
             colors["Face"] = c;
             if(wildcard.size()==4)
                 return colors;
@@ -3113,7 +3113,7 @@ std::map<std::string, App::Color> ViewProviderLink::getElementColors(const char
         while(true) {
             if(wildcard!=ViewProvider::hiddenMarker() && vp->OverrideMaterial.getValue()) {
                 auto color = ShapeMaterial.getValue().diffuseColor;
-                color.a = ShapeMaterial.getValue().transparency;
+                color.setTransparency(ShapeMaterial.getValue().transparency);
                 colors.emplace(wildcard,color);
             }
             auto link = vp->getObject()->getLinkedObject(false);
@@ -3139,7 +3139,7 @@ std::map<std::string, App::Color> ViewProviderLink::getElementColors(const char
                     if(!overrides[i])
                         continue;
                     auto color = mat.diffuseColor;
-                    color.a = mat.transparency;
+                    color.setTransparency(mat.transparency);
                     colors.emplace(std::to_string(i)+"."+wildcard,color);
                 }
             }
@@ -3284,7 +3284,7 @@ void ViewProviderLink::setElementColors(const std::map<std::string, App::Color>
     if(hasFaceColor) {
         auto mat = ShapeMaterial.getValue();
         mat.diffuseColor = faceColor;
-        mat.transparency = faceColor.a;
+        mat.transparency = faceColor.transparency();
         ShapeMaterial.setStatus(App::Property::User3,true);
         ShapeMaterial.setValue(mat);
         ShapeMaterial.setStatus(App::Property::User3,false);
diff --git a/src/Mod/Import/App/ExportOCAF2.cpp b/src/Mod/Import/App/ExportOCAF2.cpp
index babefca1c8..fdc224f490 100644
--- a/src/Mod/Import/App/ExportOCAF2.cpp
+++ b/src/Mod/Import/App/ExportOCAF2.cpp
@@ -63,7 +63,7 @@ using namespace Import;
 ExportOCAFOptions::ExportOCAFOptions()
 {
     defaultColor.setPackedValue(0xCCCCCC00);
-    defaultColor.a = 0;
+    defaultColor.a = 1;
 }
 
 ExportOCAF2::ExportOCAF2(Handle(TDocStd_Document) h, GetShapeColorsFunc func)
@@ -94,7 +94,7 @@ ExportOCAFOptions ExportOCAF2::customExportOptions()
         App::GetApplication().GetParameterGroupByPath("User parameter:BaseApp/Preferences/View");
     defaultOptions.defaultColor.setPackedValue(
         handle->GetUnsigned("DefaultShapeColor", defaultOptions.defaultColor.getPackedValue()));
-    defaultOptions.defaultColor.a = 0;
+    defaultOptions.defaultColor.a = 1;
 
     return defaultOptions;
 }
diff --git a/src/Mod/Import/App/ImportOCAF2.cpp b/src/Mod/Import/App/ImportOCAF2.cpp
index 19e8bb173d..0f8dfa7733 100644
--- a/src/Mod/Import/App/ImportOCAF2.cpp
+++ b/src/Mod/Import/App/ImportOCAF2.cpp
@@ -72,10 +72,10 @@ using namespace Import;
 ImportOCAFOptions::ImportOCAFOptions()
 {
     defaultFaceColor.setPackedValue(0xCCCCCC00);
-    defaultFaceColor.a = 0;
+    defaultFaceColor.a = 1.0F;
 
     defaultEdgeColor.setPackedValue(421075455UL);
-    defaultEdgeColor.a = 0;
+    defaultEdgeColor.a = 1.0F;
 }
 
 ImportOCAF2::ImportOCAF2(Handle(TDocStd_Document) hDoc, App::Document* doc, const std::string& name)
@@ -114,12 +114,12 @@ ImportOCAFOptions ImportOCAF2::customImportOptions()
         App::GetApplication().GetParameterGroupByPath("User parameter:BaseApp/Preferences/View");
     defaultOptions.defaultFaceColor.setPackedValue(
         hGrp->GetUnsigned("DefaultShapeColor", defaultOptions.defaultFaceColor.getPackedValue()));
-    defaultOptions.defaultFaceColor.a = 0;
+    defaultOptions.defaultFaceColor.a = 1.0F;
 
     defaultOptions.defaultEdgeColor.setPackedValue(
         hGrp->GetUnsigned("DefaultShapeLineColor",
                           defaultOptions.defaultEdgeColor.getPackedValue()));
-    defaultOptions.defaultEdgeColor.a = 0;
+    defaultOptions.defaultEdgeColor.a = 1.0F;
 
     return defaultOptions;
 }
@@ -353,9 +353,6 @@ bool ImportOCAF2::createObject(App::Document* doc,
                             hasFaceColors = true;
                             info.hasFaceColor = true;
                         }
-                        else {
-                            assert(0);
-                        }
                     }
                 }
                 if (foundEdgeColor) {
diff --git a/src/Mod/Import/App/Tools.cpp b/src/Mod/Import/App/Tools.cpp
index f052043952..6d2cdaed90 100644
--- a/src/Mod/Import/App/Tools.cpp
+++ b/src/Mod/Import/App/Tools.cpp
@@ -53,12 +53,12 @@ App::Color Tools::convertColor(const Quantity_ColorRGBA& rgba)
     return App::Color(static_cast<float>(red),
                       static_cast<float>(green),
                       static_cast<float>(blue),
-                      1.0f - static_cast<float>(rgba.Alpha()));
+                      static_cast<float>(rgba.Alpha()));
 }
 
 Quantity_ColorRGBA Tools::convertColor(const App::Color& col)
 {
-    return Quantity_ColorRGBA(Quantity_Color(col.r, col.g, col.b, OCC_COLOR_SPACE), 1.0f - col.a);
+    return Quantity_ColorRGBA(Quantity_Color(col.r, col.g, col.b, OCC_COLOR_SPACE), col.a);
 }
 
 static inline std::ostream& operator<<(std::ostream& os, const Quantity_ColorRGBA& rgba)
diff --git a/src/Mod/Import/Gui/ImportOCAFGui.cpp b/src/Mod/Import/Gui/ImportOCAFGui.cpp
index 154e1297fb..0d0f2d3f94 100644
--- a/src/Mod/Import/Gui/ImportOCAFGui.cpp
+++ b/src/Mod/Import/Gui/ImportOCAFGui.cpp
@@ -51,7 +51,7 @@ void ImportOCAFGui::applyFaceColors(Part::Feature* part, const std::vector<App::
 
     if (colors.size() == 1) {
         vp->ShapeAppearance.setDiffuseColor(colors.front());
-        vp->Transparency.setValue(100 * colors.front().a);
+        vp->Transparency.setValue(100 * colors.front().transparency());
     }
     else {
         vp->ShapeAppearance.setDiffuseColors(colors);
diff --git a/src/Mod/Part/Gui/ViewProviderExt.cpp b/src/Mod/Part/Gui/ViewProviderExt.cpp
index 0c1155035c..359ff9733a 100644
--- a/src/Mod/Part/Gui/ViewProviderExt.cpp
+++ b/src/Mod/Part/Gui/ViewProviderExt.cpp
@@ -341,13 +341,12 @@ void ViewProviderPartExt::onChanged(const App::Property* prop)
     }
     else if (prop == &_diffuseColor) {
         // Used to load the old DiffuseColor values asynchronously
-        // v0.21 used the alpha channel to store transparency values
         std::vector<App::Color> colors = _diffuseColor.getValues();
         std::vector<float> transparencies;
         transparencies.resize(static_cast<int>(colors.size()));
         for (int i = 0; i < static_cast<int>(colors.size()); i++) {
-            transparencies[i] = colors[i].a;
-            colors[i].a = 1.0;
+            transparencies[i] = colors[i].transparency();
+            colors[i].a = 1.0F;
         }
         ShapeAppearance.setDiffuseColors(colors);
         ShapeAppearance.setTransparencies(transparencies);
@@ -665,7 +664,7 @@ std::map<std::string,App::Color> ViewProviderPartExt::getElementColors(const cha
 
     if(!element || !element[0]) {
         auto color = ShapeAppearance.getDiffuseColor();
-        color.a = Transparency.getValue()/100.0f;
+        color.setTransparency(Transparency.getValue()/100.0F);
         ret["Face"] = color;
         ret["Edge"] = LineColor.getValue();
         ret["Vertex"] = PointColor.getValue();
@@ -676,7 +675,7 @@ std::map<std::string,App::Color> ViewProviderPartExt::getElementColors(const cha
         auto size = ShapeAppearance.getSize();
         if(element[4]=='*') {
             auto color = ShapeAppearance.getDiffuseColor();
-            color.a = Transparency.getValue()/100.0f;
+            color.setTransparency(Transparency.getValue()/100.0F);
             bool singleColor = true;
             for(int i=0;i<size;++i) {
                 if (ShapeAppearance.getDiffuseColor(i) != color) {
@@ -688,7 +687,7 @@ std::map<std::string,App::Color> ViewProviderPartExt::getElementColors(const cha
             }
             if(size && singleColor) {
                 color = ShapeAppearance.getDiffuseColor(0);
-                color.a = Transparency.getValue()/100.0f;
+                color.setTransparency(Transparency.getValue()/100.0F);
                 ret.clear();
             }
             ret["Face"] = color;
@@ -699,7 +698,7 @@ std::map<std::string,App::Color> ViewProviderPartExt::getElementColors(const cha
             else
                 ret[element] = ShapeAppearance.getDiffuseColor();
             if(size==1)
-                ret[element].a = Transparency.getValue()/100.0f;
+                ret[element].setTransparency(Transparency.getValue()/100.0F);
         }
     } else if (boost::starts_with(element,"Edge")) {
         auto size = LineColorArray.getSize();