Yii 2 custom dropdown menu with items not working

I'm creating my own dropdownlist function in Yii 2. I created a function and a view and in the view I have multiple items inside of my dropdown form.

<?= $form->customDropDown($dpForm, 'color', [
        'items' =>
            [
                'label' => 'red',
                'value' => 'red',
                'options' => [
                    'style' => 'color: red'
                ]
            ]
            [
                'label' => 'blue',
                'value' => 'blue',
                'options' => [
                    'style' => 'color: blue'
                ]
            ]
    ]

And the function I made looks like this (it uses and is located in ActiveForm):

    public function customDropdown($model, $attribute, $items = [], $options = [])
    {
        $value = Html::getAttributeValue($model, $attribute);

        $field = $this->field($model, $attribute, $options);

        return $this->staticOnly ? $field : $field->dropDownList($items);
    }

The problem is that when I open my dropdown, everything is either an option or an optgroup instead of just options with a label and a style.

How it looks like in Inspector:

<optgroup label='0'>
    <option value="label">red</option>
    <option value="value">red</option>
</optgroup>
<optgroup label="options">
    <option value="style">color: red</option>
</optgroup>

And so on. What I want looks like this:

<option value="red" style="color: red">red</option>

But I can't seem to get it.

To achieve the desired output where each item in the dropdown is represented by a single <option> tag with the specified label, value, and style, you need to modify your code as follows:

In your view file, update the customDropDown function call to pass the items array correctly:

<?= $form->customDropDown($dpForm, 'color', [
        [
            'label' => 'red',
            'value' => 'red',
            'options' => [
                'style' => 'color: red'
            ]
        ],
        [
            'label' => 'blue',
            'value' => 'blue',
            'options' => [
                'style' => 'color: blue'
            ]
        ],
    ]
); ?>

Updated method:

    public function customDropdown($model, $attribute, $items = [], $options = [])
{
    $value = Html::getAttributeValue($model, $attribute);

    $field = $this->field($model, $attribute);

    $options['options'] = array_column($items, 'options');
    $options['prompt'] = '';

    return $this->staticOnly ? $field : $field->dropDownList(array_column($items, 'label', 'value'), $options);
}

In this updated version, we pass the $options array directly to the dropDownList method and use array_column to extract the label-value pairs from the $items array.