When selecting colours/icons under "Add New Container", you'll be able to select two different colours/icons. However, this doesn't really cause any issues when creating containers and seems to be a simple UI problem. Users shouldn't be able to create two different circle selectors. Quick video of the issue occurring (also attached a screenshot) * https://youtu.be/znGCqND77fc STR: * open fx and visit about:preferences#containers * select "Add New Container" * click on any colour so you get the black circle selector * now click on another colour, hold the mouse click and slowly drag the mouse pointer away from the colour selection You'll notice that two colours will be selected at the same time using two different selector indicators. One will be coloured black, which is the original selector and the other will be coloured blue.

You can reproduce this by quickly clicking through the items as well. Eventually, you'll notice the circle selector going blue rather than using the default "black" colour. Added a quick example below: * https://youtu.be/FvQxIypAgpM

Needinfoing myself to remind myself to look into the STR's of this :).

Under Ubuntu/Windows, the circle selectors initially appearing as black. Once you start selecting other icons or colours, the circle selector will be blue. However, under macOS, the circle selector stays black the entire time other than getting a blue circle selector when initiating the bug mentioned in comment#0. We should try keeping everything consistent on all the different platforms. I've created a short video [1] to illustrate the above point. [1] https://youtu.be/47fjS86O8sY

Bulk change per https://bugzilla.mozilla.org/show_bug.cgi?id=1401020

I'm going to clear the NI, it's not currently on my plate or high priority by any means. I'm happy to work through this with anyone etc if they want to take it.