make_colormap.js

gistfile1.txt

let colormap = require('colormap')
var fs = require('fs');

let map_name = 'bluered';
let file_name = map_name + ".json"

let colors = colormap({
    colormap: map_name,
    nshades: 100,
    format: 'hex',
    alpha: [1.0, 0.5, 1.0]
})

var json_text = JSON.stringify(colors);

fs.writeFile(file_name, json_text, function(err) {
    if(err) {
        return console.log(err);
    }
    console.log("Created " + file_name);
});