<body style="background:#FFFFFF;">
<div style="width:620px;margin:20px auto 0 auto;">
<canvas id="wheelcanvas" width="500" height="500" style="background:#FFFFFF;"></canvas>
<script type="text/javascript">
var colors = [ "#069ffd", "#fff" ];
var canvas = document.getElementById("wheelcanvas");
ctx = canvas.getContext("2d");
ctx.clearRect(0,0,500,500);
ctx.arc(250, 250, outsideRadius, 0, Math.PI*2, false);
ctx.arc(250, 250, 120, 0, Math.PI*2, false);
for(var i = 0; i < 4; i++) {
var angle = startAngle + i * arc;
ctx.fillStyle = colors[i%2];
ctx.arc(250, 250, insideRadius, angle, angle + arc, false);
ctx.arc(250, 250, 0, angle + arc, angle, true);
ctx.font = "normal 70px 'Arial'";
ctx.textAlign = "center";
ctx.rotate(-45*Math.PI/180);
ctx.fillText("B",-20,-140);
ctx.fillText("M",0,-130);
ctx.rotate(45*Math.PI/180);
ctx.fillText("W",20,-140);