#myCanvas
addColorStop
0.3,'red'| 0.4,'red'| 0.5,'red'| 0.6,'red'| 0.6,'#0000FF'| 0.6,'orange'| 0.6,'rgb(0,255,255)'
const grd = ctx.createLinearGradient(0,0,150,0);
grd.addColorStop(#val);
grd.addColorStop(0.7,'green');
ctx.fillStyle = grd;
ctx.fillRect(0,0,150,100);