Control how RVAltCtrl looks, and which units it uses for temperature and tire pressure, from Settings → Display and Units.
Appearance
Choose Light, Dark, or System. Light shows RVAltCtrl with a bright background and dark text, the usual look for most apps and websites. Dark shows it with a dark background and light text instead, easier on the eyes in a dim RV at night and easier on battery for phones with an OLED screen. System follows whatever your phone, tablet, or computer's own light/dark setting is, and switches automatically whenever that changes.
You can change these help pages the same way, click Theme in the upper right to switch between light and dark here too. RVAltCtrl's own device pages, the my.rvaltctrl.com portal, and these help pages all try to stay in sync with your current Light or Dark mode preference as you move between them.
Temperature Units
Choose °F (Fahrenheit) or °C (Celsius). This applies to every temperature reading throughout the app: climate zones, wireless temperature sensors, tank temperatures, and anywhere else a temperature shows up.
Pressure Units
Choose PSI or bar. This applies to TPMS tire pressure readings.
Where these settings live
Unlike most other settings pages, there's no Save button here, each choice takes effect the moment you tap it. These are also saved to the browser you're using, not to the RVAltCtrl device itself, so a different phone, tablet, or computer viewing the same device can have its own independent Appearance and unit choices.