Hi, Matthew 

Sorry for the delay

I just did some testing. To be honest with you, i am still checking all the bits and pieces the devs added to the customization of the new form,  

and it is in "beta phase", so we still got some ironing out to do.

I am using this Twenty Nineteen theme on my Test WP site,  and for me, just using the default settings of the Form,

i can see clearly all the steps are being highlighted on the left side, to indicate for the customer what they did, where they are, and what is next.

I sent you a video attachment to see how it looks from my end;

At this time, at the Amelia Customization setting,

 you can choose the colours for the "highlight circle", and the "checkmark";  to indicate for the customers what they went through;

Right now, we can only change the entire sidebar background area color;  but not only the sidebar container elements which they "already covered", as you pointed out in your screenshot.

But i like this idea to further enhance the customization of the sidebar, 

so if you can be so kind, please feel free to search through our feature suggestion page, 

 to see if someone may be already suggested this feature. If you can't see it, feel free to add your suggestion there, and as more people vote, the feature will move higher on the priority list.

You can certainly follow our changeLog page if you'd like, where we state any changes/new features/bug fixes during updates;

and our newsletter, so you're informed about new features, bug fixes, freebies, etc.

Maybe this can be achieved right now with some customizations, but i did my best effort and could not find a way since they all share the same CSS class;

we can only cover some basic customizations, and this would take a higher level, that is not covered by our support.

So we will have to wait a bit for the devs to add more customization options to the new Form, I'm afraid.