javascript color green to red
function perc2color(perc) { var r, g, b = 0; if (perc < 50) { r = 255; g = Math.round(5.1 * perc); } else { g = 255; r = Math.round(510 - 5.10 * perc); } var h = r * 0x10000 + g * 0x100 + b * 0x1; return '#' + ('000000' + h.toString(16)).slice(-6); }