js 颜色渐变
function GetColor(val,tt) {
if(tt>1){
tt = tt-1;
}
var one = (255 + 255) / tt;
var r = 0, g = 0, b = 0;
if (val < tt/2) {
r = (one * val);
g = 255;
}
else if (val >= tt/2 && val < tt) {
r = 255;
g = 255 - ((val - tt/2) * one);
}
else { r = 255; }
return 'rgb(' + r + ', ' + g + ', ' + b + ')';
}
var ss = 'js获取渐变颜色，效果演示'
for(var i=0;i<ss.length;i++){
document.write('<span style="background:'+GetColor(i,tt)+'">'+ss.charAt(i)+'</span >')
}