How can I create a function for the color in decreasing order

Question

I am creating a functionality to create the image like this Image link I mean that I want to display the color like

1. 0 %-1 % green to light green
2. 1%-3% yellow to light yellow
3. 3%-5% orange to light orange
4. 5% - 6 red to dark red

Currently, I think it is only possible with the if else condition.

I am doing this in the following way:

 function getBackground($val) {
    if($val<=0.3)
        return "#0A3A0A";
    if($val< 0.5) 
        return "#1E4E1E";
    if($val< 1) 
        return "#508050";

    if($val< 1.4) 
        return "#FFFF0A"; 
    if($val< 1.8) 
        return "#FFFF1E";  
    if($val< 2) 
        return "#FFFF32";  
    if($val< 2.4) 
        return "#FFFF46";     
    return "red";
}

and in html in this way. It is in loop 1-15

 $class=getBackground($val);
echo "<li style='background:{$class}'>{$val}%</li>";

but I don't think this is a good solution, because I have to create if else for every condition .

Is there a better way to do this? if yes, then please suggest it to me.

Update:

Main issue is:

The colors will behave like this if it is 0.2% the color will bright green and if it is o.6% it will light green and so on. If it is 0.9% it will lighter green .

I am looking for a solution to show different color like if value is 0.1 then dark green , if it is 0.1 less dark green ................. 0.9 the lighter green . similarly if val is 1.1 then dark yellow. if it is 1.2 less dark yellow........ 1.9 lighter yellow. something like this

Answer 1

This should work for you:

Just put your colors into an array with a certain range. Then loop through all colors and if the $val is in the range assign the color to $class and break the loop.

<?php

    $arr = [
            "green" => ["start" => 0, "end" => 1],
            "yellow" => ["start" => 1, "end" => 3],
            "orange" => ["start" => 3, "end" => 5],
            "red" => ["start" => 5, "end" => 6],
        ];

    $class = "default";
    foreach($arr as $color => $range) {
        if($val <= $range["end"] && $val >= $range["start"]) {
            $class = $color;
            break;
        }
    }

?>

EDIT:

As from your updated code, this should work for you:

<?php

    $arr = [
            ["start" => 0, "end" => 0.3, "color" => "#0A3A0A"],
            ["start" => 0.3, "end" => 0.5, "color" => "#1E4E1E"],
            ["start" => 0.5, "end" => 1, "color" => "#508050"],
            ["start" => 1, "end" => 1.4, "color" => "#FFFF0A"],
            ["start" => 1.4, "end" => 1.8, "color" => "#FFFF1E"],
            ["start" => 1.8, "end" => 2, "color" => "#FFFF32"],
            ["start" => 2, "end" => 2.4, "color" => "#FFFF46"],
        ];

    $class = "red";
    foreach($arr as $range) {
        if($val <= $range["end"] && $val >= $range["start"]) {
            $class = $range["color"];
            break;
        }
    }

?>

EDIT 2:

Since you don't want "static" values, this should work for you:

<?php

    $arr = [
            ["start" => 0, "end" => 0.8, "colorStart" => "FFE6E6", "colorEnd" => "4C0000", "interval" => ""],
            ["start" => 0.8, "end" => 1.8, "colorStart" => "C2FFC2", "colorEnd" => "296629", "interval" => ""],
            ["start" => 1.8, "end" => 2.7, "colorStart" => "C2C2FF", "colorEnd" => "6666FF", "interval" => ""],
        ];


    $arr = array_map(function($v){
        $steps = intval((($v["end"] - $v["start"]) * 10));
        list($redStart, $greenStart, $blueStart) = array_map("hexdec", str_split($v["colorStart"], 2));
        list($redEnd, $greenEnd, $blueEnd) = array_map("hexdec", str_split($v["colorEnd"], 2));

        $interval = sprintf("%02d", intval(($redStart - $redEnd) / $steps)) . sprintf("%02d", intval(($greenStart - $greenEnd) / $steps)) . sprintf("%02d", intval(($blueStart - $blueEnd) / $steps));
        return array_merge($v, ["interval" => $interval]);
    }, $arr);


    $val = 1.1;
    $class = "FF0000";
    foreach($arr as $range) {
        if($val < $range["end"] && $val >= $range["start"]) {
            $class = "";
            $multiplier = intval((($val - $range["start"]) * 10));
            list($redAdd, $greenAdd, $blueAdd) = array_map(function($v)use($multiplier){return dechex($v*$multiplier);}, str_split($range["interval"], 2));
            list($redStart, $greenStart, $blueStart) = str_split($range["colorStart"], 2);
            list($redEnd, $greenEnd, $blueEnd) = str_split($range["colorEnd"], 2);

            $colors = ["red", "green", "blue"];

                foreach($colors as $color) {
                    if(hexdec(${$color . "End"}) > hexdec(${$color . "Start"}))
                        $r = hexdec(${$color . "Start"}) + hexdec(${$color. "Add"});
                    else
                        $r = hexdec(${$color . "Start"}) - hexdec(${$color. "Add"});
                    $class .= sprintf("%02X", ($r >= 0 && $r <= 255 ? $r : ($r<0?0:255)));
                }

            break;
        }
    }

    echo "<div style='hight:100px;width:200px;background-color:#$class;'>some text</div>";

?>

Demo