Is there any way to make snap installed apps look more native?

Solution 1:

You can monitor this link: Use the system gtk theme and the latest, as of now, is this which has a lot of specific links.

With these latter pieces landing, themes will be unblocked. The very first version of the feature will leverage a single snap containing a number of common themes which can be used as the default-provider in content interfaces in client applications. This is easy to do and will get us good looking applications in the short term.

Later we’ll then introduce improvements that will allow finding and installing snaps providing arbitrary themes that match the local environment needs. We have initial ideas here but the details still need to be designed.

So, work is in progress and the intention to make snaps appear "more integrated" is there.