New Planner stuck in dark mode and can't change per-plan backgrounds

Update : a background is back to my web-app Planner (the last one I used before the "blackout" update), but I haven't got control of it in app. I can only change the upper band in the settings :

It seems some work is in progress, but it still looks unfinished.

My Planner's web client relies on the browser's settings rather than having its own light mode settings. 

I'm on Windows 10 and had to go into Firefox's browser settings and select Light Mode to get Planner to change. None of my other 365 apps use the browser's appearance settings, which is an annoying oversight. 

I found a solution, but it's kind of weird. My planner follows whatever mode I'd set in Windows 11. It totally ignores the mode in my Chrome browser. 

Anyone see this behavior too?

I think I found a solution.  The issue is in Edge, and to resolve it you need to go to this address edge://settings/appearance and change the setting there.  I realized that not only was my Planner stuck in dark mode, but Edge too, and the change here fixed Planner for me.

+1 on this - have submitted feedback, in the meantime have switched browser to light theme. Doh.

Ok, I've got something to slightly improve this situation. It's not smart backgrounds, but it makes Planner more attractive if you access it via the web like I do.

In your browser, install the Stylebot extension. Enable and open it when you have Planner for the Web open. In the "Code" section, paste in the following CSS:

.planTaskBoardPage {
  background-color: transparent;
  background-image: url('https://4kwallpapers.com/images/wallpapers/windows-11-stock-grey-abstract-dark-background-3840x2160-8957.png');
  background-size: contain;
}

Modify the URL to a nice background image of your choosing. Stylebot will apply this CSS change whenever you return to Planner

If you know how to Inspect the page and tailor CSS elements, you can go and have some fun making Planner look like exactly what you want it to be (until next time Microsoft update something). Just put your changes into Stylebot so they are sticky.

I'm also facing this issue ... I prefer Dark Mode for Windows OS system settings and most applications, but NOT Planner ... drove myself crazy looking for the settings (which now also appear to be completely gone) and couldn't find any way to change the theme.

I changed my Outlook Web theme to Light and Planner doesn't even respect that.

Please bring back the option to change Dark Mode / Light Mode as well as the options to set different backgrounds per Planner as noted by others above.

BrettR20 

Smart background was actually very useful to add visual confort and recognition to Plans in the webapp.

+1 to get the Smart background feature back!

"Paint it, Black" by the Rolling Stones is now stuck in my head every time I use the new Planner.

https://www.youtube.com/watch?v=EBUFtoC2oj4

Ug, please fix this.