Here are step by step instructions on how to change it:
1. Login to eSelect Plus
2. Click on Admin in top navigation
3. Click on Hosted Config in top submenu
4. Find ps_store_id in list of Version 3 Hosted Paypage Configuration you would like to change and click on Edit
5. Click on Configure Appearance under Paypage Appearance
On that page under Colors and Styles you can change quite a few things:
But changing those options most likely will not bring expected results, page will not look like your site, and there is simple workaround: You can use Moneris Hosted Payapge in the IFrame inside your own site.