Hi @tnaftali,
Welcome to the Community!
If your tenant has a custom domain, you can use page templates for the New Universal Login page to achieve this. This is done through the Management API, and you can read more about this option in the docs:
If you do not have a custom domain, you can switch the the Classic Universal Login experience and customize the template based on the application. This is done through your Auth0 dashboard (Branding > Universal Login). After switching to Classic, you can navigate to the Login tab and enable Customize Login Page to update the template. You can determine which app the login is for by using config.clientID. You can pass configs for the logo in the Lock configs:
https://auth0.com/docs/libraries/lock/lock-configuration#theme