<form name="data">
    {$formh}
    <a
        class="button color green oppose"
        onclick="{$submitdata}"
    >
        {$c->__('button.validate')}
    </a>
</form>

<form name="data">
    {$formh}
    <a
        class="button color oppose"
        onclick="{$submitdata}"
    >
        {$c->__('button.validate')}
    </a>
</form>

Remove the green color of the button
Remove the green color of the button
