JSFiddle - React, Tailwind, and code Playground
HTML
<canvas id="canvas1" width="500" height="500"></canvas>http://jsfiddle.net/9bMPD/http://jsfiddle.net/9bMPD/
JavaScript
var can = document.getElementById('canvas1');
var ctx = can.getContext('2d');
// linear gradient from start to end of line
var grad= ctx.createLinearGradient(50, 150, 150, 150);
grad.addColorStop(0, "red");
grad.addColorStop(1, "green");
ctx.strokeStyle = grad;
ctx.beginPath();
ctx.lineWidth = 1;
ctx.moveTo(50.5,150.5);
ctx.lineTo(150.5,150.5);
ctx.stroke();