Random color generation using PHP

Question

I\'m trying to generate random HTML colors in PHP, but I\'m having trouble getting them to look similar, or in the same family. Is there some function I can use to generate

Answer 1

function randomColor() {
$str = '#';
for ($i = 0; $i < 6; $i++) {
    $randNum = rand(0, 15);
    switch ($randNum) {
        case 10: $randNum = 'A';
            break;
        case 11: $randNum = 'B';
            break;
        case 12: $randNum = 'C';
            break;
        case 13: $randNum = 'D';
            break;
        case 14: $randNum = 'E';
            break;
        case 15: $randNum = 'F';
            break;
    }
    $str .= $randNum;
}
return $str;}

Answer 2

Try this:

//For every hex code
$random = mt_rand(0, 16777215);
$color = "#" . dechex($random);

And than you can just use it like this:

background-color: <?php echo $color ?>;

Answer 3

I'd just limit the range of the rand()-params:

// full color palette (32 bit)
for($index = 0; $index < 30; $index++)
{
    echo '<div style="background-color: #' . dechex(rand(0,16777215)) . '; display: inline-block; width: 50px; height: 50px;"></div>';
}
echo '<br />';

// pastell colors
for($index = 0; $index < 30; $index++)
{
    echo '<div style="background-color: rgb(' . rand(128,255) . ',' . rand(128,255) . ',' . rand(128,255) . '); display: inline-block; width: 50px; height: 50px;"></div>';
}
echo '<br />';

// dark colors
for($index = 0; $index < 30; $index++)
{
    echo '<div style="background-color: rgb(' . rand(0,128) . ',' . rand(0,128) . ',' . rand(0,128) . '); display: inline-block; width: 50px; height: 50px;"></div>';
}
echo '<br />';

// shades of blue
for($index = 0; $index < 30; $index++)
{
    echo '<div style="background-color: rgb(' . rand(0,56) . ',' . rand(0,56) . ',' . rand(0,255) . '); display: inline-block; width: 50px; height: 50px;"></div>';
}
echo '<br />';

// shades of green
for($index = 0; $index < 30; $index++)
{
    echo '<div style="background-color: rgb(' . rand(0,56) . ',' . rand(0,255) . ',' . rand(0,56) . '); display: inline-block; width: 50px; height: 50px;"></div>';
}
echo '<br />';

// shades of red
for($index = 0; $index < 30; $index++)
{
    echo '<div style="background-color: rgb(' . rand(0,255) . ',' . rand(0,56) . ',' . rand(0,56) . '); display: inline-block; width: 50px; height: 50px;"></div>';
}

Answer 4

RandomColor has been ported to PHP, you can find it here. With it it's also possible to have random light or random dark colors.
Example Usage:

include('RandomColor.php');
use \Colors\RandomColor;
// Returns a hex code for a 'truly random' color
RandomColor::one(array(
   'luminosity' => 'random',
   'hue' => 'random'
));
// Returns a hex code for a light blue
RandomColor::one(array(
   'luminosity' => 'light',
   'hue' => 'blue'
));

Answer 5

A few years ago I came across this class. It lets you generate complimentary colors based on a seed value.

If you're looking for something more general, limit yourself to a general range using rand (obviously below 255) and the use base_convert.

Answer 6

Found something much nicer posted on the blog of someone called Craig Lotter:

$randomcolor = '#' . dechex(rand(0,10000000));