How to make custom button styles for 'overlay' instances (when on index pages with backgrounds)

I'd like to change the 'overlay' behavior of a button (im using a whilte/light background image and need to have an alternate button style so it can be seen but only in this one section). I've been able to figure it out for H classes and text but the buttons seem to allude me. Thanks!- js

Hi,

What is page url? We can check easier