Label:Fixed the color of letter will be overridden by fade action.

cocos/2d/CCLabel.cpp

@@ -1525,6 +1525,11 @@ void Label::updateDisplayedColor(const Color3B& parentColor)
             _shadowNode->updateDisplayedColor(_displayedColor);
         }
     }
+
+    for (auto it : _letters)
+    {
+        it.second->updateDisplayedColor(_displayedColor);;
+    }
 }
 
 void Label::updateDisplayedOpacity(GLubyte parentOpacity)
@@ -1539,6 +1544,11 @@ void Label::updateDisplayedOpacity(GLubyte parentOpacity)
             _shadowNode->updateDisplayedOpacity(_displayedOpacity);
         }
     }
+
+    for (auto it : _letters)
+    {
+        it.second->updateDisplayedOpacity(_displayedOpacity);;
+    }
 }
 
 void Label::setTextColor(const Color4B &color)

tests/cpp-tests/Classes/LabelTest/LabelTestNew.cpp

@@ -81,6 +81,7 @@ NewLabelTests::NewLabelTests()
     ADD_TEST_CASE(LabelIssue12409Test);
     ADD_TEST_CASE(LabelAddChildTest);
     ADD_TEST_CASE(LabelIssue12775Test);
+    ADD_TEST_CASE(LabelIssue11585Test);
 };
 
 LabelTTFAlignmentNew::LabelTTFAlignmentNew()
@@ -2017,3 +2018,29 @@ std::string LabelIssue12775Test::subtitle() const
 {
     return "Should not crash if the font not contain a Unicode charmap.";
 }
+
+LabelIssue11585Test::LabelIssue11585Test()
+{
+    auto center = VisibleRect::center();
+
+    auto label = Label::createWithTTF("Hello World", "fonts/arial.ttf", 24);
+    label->setPosition(center.x, center.y);
+    addChild(label);
+
+    label->getLetter(0)->setColor(Color3B::RED);
+    label->getLetter(1)->setColor(Color3B::GREEN);
+    label->getLetter(2)->setColor(Color3B::BLUE);
+    auto action = RepeatForever::create(Sequence::create( 
+        FadeOut::create(2), FadeIn::create(2),nullptr));
+    label->runAction(action);
+}
+
+std::string LabelIssue11585Test::title() const
+{
+    return "Test for Issue #11585";
+}
+
+std::string LabelIssue11585Test::subtitle() const
+{
+    return "The color of letter should not be overridden by fade action.";
+}

tests/cpp-tests/Classes/LabelTest/LabelTestNew.h

@@ -619,4 +619,15 @@ public:
     virtual std::string subtitle() const override;
 };
 
+class LabelIssue11585Test : public AtlasDemoNew
+{
+public:
+    CREATE_FUNC(LabelIssue11585Test);
+
+    LabelIssue11585Test();
+
+    virtual std::string title() const override;
+    virtual std::string subtitle() const override;
+};
+
 #endif