I don’t think that this is an accurate characterization. There’s a complete API documentation pull-down on the top of every single forum web page, and a whole section of this forum dedicated to third-party integrations and apps that will display your station’s data nine ways to Sunday…and none of them purple.
If you don’t like their colors, feel free to make your own app!
Let me add a confession that I have not opened the Tempest app once since the purple version was released. My home weather station console is a wall-mounted tablet displaying the WeeWX Belchertown skin 24/7 in dark mode. That’s one of the big plusses of the Tempest ecosystem. You’re NOT locked in to using the purple app for anything but changing the configuration settings of your station.
If you want something to compare it to, I spent more than a Tempest station sells for to buy the API documents from Davis for their pre-Vantage serial logger. Talk about criminal, they charged hundreds of dollars for a multi-generation photocopy of some programmer’s notes and a floppy disc with obsolete sample code for an equally obsolete C compiler. Please click on the API pull-down at the top of this page now. if for no other reason than you CAN look at current/useful Tempest API documentation for free…