I’ve always thought the long running “Multi-Account Containers” in Firefox was a better implementation of this idea than having to switch profiles and open a whole new window, when often what I need is a tab or two for a profile other than the one I’m in. You can even configure proxies to run on a per-container basis if that’s useful. But I can certainly understand wanting to better separate what your working on then just tabs with colored indicators to remind you which is which at a glance.
https://support.mozilla.org/en-US/kb/containers