darkcodes

Here is my solutions

At line 399 replace:

// Replace values which should be returned as transparent
if (in_array($value['value'], $map_to_transparent)) {
    $value['value'] = 'transparent';
}

With:

if (is_array($value) && array_key_exists('value', $value)
    && in_array($value['value'], $map_to_transparent)) {
    // Replace values which should be returned as transparent
    $value['value'] = 'transparent';
} elseif (in_array($value, $map_to_transparent)) {
    $value          = [];
    $value['value'] = 'transparent';
}