One of the main reasons I love Newton is the user experience and design has (or had now) very clean and focused content hierarchy. This was achieved with an elegant design that emphasizes what is important to the user above all else.
The last update has decreased those important aspects with design changes that feel cluttered to me, like bolding too much of the email previews on mobile.
I would love to have more granular control over the look and feel of the app by choosing my own text colors and styles, as well as tweaking backgrounds and other elements to my visual preference.
From a technical POV this shouldn’t be too difficult to implement. I hope to see this as a new feature soon so that we can tailor the experience to our preference.