customization_iframe_emails.php

<?php
    // WePay PHP SDK - http://git.io/mY7iQQ
    require 'wepay.php';

    // application settings
    $account_id = 123456789;
    $client_id = 123456789;
    $client_secret = "1a3b5c7d9";
    $access_token = "1a3b5c7d9";

    // create a theme
    $theme = array(
        'name'              => 'My Sample Theme',
        'primary_color'     => 'FFFFFF',
        'secondary_color'   => '000000',
        'background_color'  => '004C64',
        'button_color'      => '0084A0'
    );

    // change to useProduction for live environments
    Wepay::useStaging($client_id, $client_secret);

    $wepay = new WePay($access_token);

    // modify your account
    $response = $wepay->request('account/modify', array(
        'account_id'    => $account_id,
        'theme_object'  => $theme
    ));

    // display the response
    print_r($response);
?>