Custom palette in JSROOT

[dastudillo]

I don’t know if this works for JSROOT, but maybe you can give it a try and see (it might also explain why you get two bins with the same colour):

How to set color with `gStyle->SetPalette` for first bin and last bin? may be bugs

Create a text file (e.g. “mycolours.txt”) with the RGB values (one colour per line, R G B separated by space) and use TColor::CreateColorTableFromFile #include <TStyle.h> #include <TFile.h> #include <TH2F.h> void p3_draw() { const int n = 6; Int_t MyPalette[n]; Int_t FI = TColor::CreateColorTableFromFile("mycolours.txt"); for (int i = 0; i < n; i++) MyPalette[i] = FI + i; gStyle->SetPalette(n, MyPalette); gStyle->SetNumberContours(n); gStyle->SetOptStat(0); TH2F* h2 = …