六种颜色选一种自高向下

 protected string getColor(int max, int min, int curhot)
    {
        int step = (max - min) / 6;
        if (curhot < step + min)
        {
            return "#b8e380";
        }
        else if (curhot < step * 2 + min)
        {
            return "#9ed456";
        }
        else if (curhot < step * 3 + min)
        {
            return "#95c333";
        }
        else if (curhot < step * 4 + min)
        {
            return "#7fab14";
        }
        else if (curhot < step * 5 + min)
        {
            return "#628e0d";
        }
        else
        {
            return "#48700a";
        }
    }