A simple radial gradient
<!DOCTYPE html> <html> <head> <style> #canvas { // www .j a va2s. co m border:1px solid #03F; background:#CFC; } </style> </head> <body> <canvas id="canvas" width="640" height="480"></canvas> <script> let context = document.getElementById('canvas').getContext('2d'); let gr = context.createRadialGradient(50,50,25,50,50,100); // Add the color stops. gr.addColorStop(0,'rgb(255,0,0)'); gr.addColorStop(.5,'rgb(0,255,0)'); gr.addColorStop(1,'rgb(255,0,0)'); // Use the gradient for the fillStyle. context.fillStyle = gr; context.fillRect(0, 0, 200, 200); </script> </body> </html>