RGB颜色值转换为十进制

//将RGB的值分别移位
c = (components.r << 16) + (components.g << 8) + (components.b);
//解析数据
var components = {
    r: (c & 0xff0000) >> 16, 
    g: (c & 0x00ff00) >> 8, 
    b: (c & 0x0000ff)
};