Add custom assignment operator to TColor to match constructor

core/base/inc/TColor.h

@@ -36,6 +36,7 @@ public:
    TColor(Int_t color, Float_t r, Float_t g, Float_t b, const char *name="", Float_t a = 1);
    TColor(Float_t r, Float_t g, Float_t b, Float_t a = 1);
    TColor(const TColor &color);
+   TColor &operator=(const TColor &color);
    virtual ~TColor();
    const char   *AsHexString() const;
    void          Copy(TObject &color) const;

core/base/src/TColor.cxx

@@ -1069,6 +1069,12 @@ TColor::TColor(const TColor &color) : TNamed(color)
    ((TColor&)color).Copy(*this);
 }
 
+TColor &TColor::operator=(const TColor &color)
+{
+   ((TColor &)color).Copy(*this);
+   return *this;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 /// Initialize colors used by the TCanvas based graphics (via TColor objects).
 /// This method should be called before the ApplicationImp is created (which