The color of the search bar for Private Browsing is indistinguishable from that of Normal Browsing when in dark mode. The Private search bar is very slightly darker, but you cannot tell unless you put the two search bars side by side.
This means it’s impossible to know which browsing mode you’re in without opening the tab manager, and you might accidentally switch to normal browsing mode without realizing.
Attached is a of normal and private browsing in dark mode.
Please dramatically increase the contrast between the private and normal search bars in dark mode.