The model-driven app themes need a complete overhaul
Today's theme editor is outdated, leaves a lot to be desired, and only works partially for some UI components (since it was originally built for the Dynamics 365 legacy applications). A complete overhaul is therefore needed of the theme configuration options to allow app makers to build the applications that their users/clients truly deserve.
A default theme should be allowed to be configured per environment - but app makers should ALSO be able to override the theme for the individual model-driven applications that are being built. Different applications should simply be allowed to use different colors and logos.
2. Navigation bar | text + icon color
The color used for the text and icons on the navigation bar should NOT be automatically determined by the fill color of the navigation bar. Instead, app makers should be able to define it as a part of the theme.
3. Site map | fill color
App makers should be able to configure the fill color of the site map (i.e. the left-side menu). Currently, no configuration options are available (the available only option is light gray). This makes all dark-mode themed custom pages look awful, and prevents app makers from defining a more vibrant UI. It would be nice if app makers could also define a fill color gradient.
4. Site map | text color + hover fill + pressed fill
If app makers are allowed to configure the fill color of the site map, then they should also be allowed to configure the text color of the area, group and subarea components within a site map. In addition, they should be allowed to define the color of the subarea (menu) buttons during a hover state and pressed state.
5. Site map | box-shadows + border-radius
Most modern UI component libraries are characterized by a soft, layered design that is brought on by the use of shadows and round edges. It would be great if we could have something similar within Power Apps - e.g. by allowing app makers to define CSS-properties like box-shadow and border-radius for the site map.
6. Section | box-shadow + border-radius + fill + color of section label
It would be great if Microsoft allowed app makers to customize the look and fell of the sections (groupings of fields) within a model-driven app. At a minimum, I would love to be able to define box-shadows, the border-radius, and the background-color of the sections. It would also be nice if app makers were allowed to define the color and the font weight of the section labels.
7. Forms | background fill
It would be great if app makers were allowed to adjust the color of the backgrounds of model-driven forms to something else than white. Our users would probably appreciate colors that are less eye-constraining.
8. Mobile client | header fill
App makers should be able to control the header fill when the app is being used on a mobile device. Currently, all model-driven apps have a dark blue header. The dark blue color might not always harmonize with the general theme of the app (e.g. if you have built a custom page with a set of colors that does not match the hard-coded dark blue header).
9. Multiple themes per app
Allow the app makers to define multiple themes per app that the users can select from (e.g. light vs. dark theme).
Define this user setting as something that can be selected by the individual users on an app-level (and not per environment).
Expose the user settings in a table that can be accessed from a custom page/embedded canvas app, so that app makers have the ability to align the selected theme with the theme being used within a custom page/embedded canvas app.
Ensure that app makers can upload multiple site map icons (i.e. one for each subarea/theme combination), so that we can avoid scenarios where we can only use icons with one color on top of a site map that can have multiple colors (dark icons on a dark site map isn't a great combination).