You change it in the Tasks_model.php. This is the function:
public function get_statuses()
{
$statuses = hooks()->apply_filters('before_get_task_statuses', [
[
'id' => static::STATUS_NOT_STARTED,
'color' => '#64748b',
'name' => _l('task_status_1'),
'order' => 1,
'filter_default' => true,
],
[
'id' => static::STATUS_IN_PROGRESS,
'color' => '#3b82f6',
'name' => _l('task_status_4'),
'order' => 2,
'filter_default' => true,
],
[
'id' => static::STATUS_TESTING,
'color' => '#0284c7',
'name' => _l('task_status_3'),
'order' => 3,
'filter_default' => true,
],
[
'id' => static::STATUS_AWAITING_FEEDBACK,
'color' => '#84cc16',
'name' => _l('task_status_2'),
'order' => 4,
'filter_default' => true,
],
[
'id' => static::STATUS_COMPLETE,
'color' => '#22c55e',
'name' => _l('task_status_5'),
'order' => 100,
'filter_default' => false,
],
]);
usort($statuses, function ($a, $b) {
return $a['order'] - $b['order'];
});
return $statuses;
}