Generating a random hex color code with PHP

I'm working on a project where I need to generate an undefined number of random, hexadecimal color codes…how would I go about building such a function in PHP?

An RGB hex string is just a number from 0x0 through 0xFFFFFF, so simply generate a number in that range and convert it to hexadecimal:

function rand_color() {
    return '#' . str_pad(dechex(mt_rand(0, 0xFFFFFF)), 6, '0', STR_PAD_LEFT);
}

or:

function rand_color() {
    return sprintf('#%06X', mt_rand(0, 0xFFFFFF));
}

Get a random number from 0 to 255, then convert it to hex:

function random_color_part() {
    return str_pad( dechex( mt_rand( 0, 255 ) ), 2, '0', STR_PAD_LEFT);
}

function random_color() {
    return random_color_part() . random_color_part() . random_color_part();
}

echo random_color();

you can use md5 for that purpose,very short

$color = substr(md5(rand()), 0, 6);

$rand = str_pad(dechex(rand(0x000000, 0xFFFFFF)), 6, 0, STR_PAD_LEFT);
echo('#' . $rand);

You can change rand() in for mt_rand() if you want, and you can put strtoupper() around the str_pad() to make the random number look nicer (although it’s not required).

It works perfectly and is way simpler than all the other methods described here :)

Valid hex colors can contain 0 to 9 and A to F so if we create a string with those characters and then shuffle it, we can grab the first 6 characters to create a random hex color code. An example is below!

code

echo '#' . substr(str_shuffle('ABCDEF0123456789'), 0, 6);

I tested this in a while loop and generated 10,000 unique colors.

code I used to generate 10,000 unique colors:

$colors = array();
while (true) {
   $color          = substr(str_shuffle('ABCDEF0123456789'), 0, 6);
   $colors[$color] = '#' . $color;
   if ( count($colors) == 10000 ) {
      echo implode(PHP_EOL, $colors);
      break;
   }
}

Which gave me these random colors as the result.

outis pointed out that my first example couldn't generate hexadecimals such as '4488CC' so I created a function which would be able to generate hexadecimals like that.

code

function randomHex() {
   $chars = 'ABCDEF0123456789';
   $color = '#';
   for ( $i = 0; $i < 6; $i++ ) {
      $color .= $chars[rand(0, strlen($chars) - 1)];
   }
   return $color;
}
    
echo randomHex();

The second example would be better to use because it can return a lot more different results than the first example, but if you aren't going to generate a lot of color codes then the first example would work just fine.

Generating a random hex color code with PHP

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