void SetLineColor(Color_t color = 1);
TH1D *hist = new TH1D("hist", "Example Histogram", 100, 0, 10); hist->SetLineColor(kRed);
TColor *myColor = new TColor(10000,0.0,0.5,0.5); TH1D *hist = new TH1D("hist", "Example Histogram", 100, 0, 10); hist->SetLineColor(myColor);In these examples, we are setting the line color of a `TH1D` histogram to either `kRed` or a custom `TColor` object. The `TColor` object can be created with a unique RGB value using its constructor. The `TH1D` class and `TColor` class are part of the ROOT package library, which is a popular set of C++ libraries used for data analysis in particle physics.