Field background color mixing with file display border color

When I set the "Field background" color it works properly everywhere except for the location bar in the source Lister toolbar. There, the color mixes with the "File display border - Source" background color.

Is there a way to disable this color mixing?

It always mixes since the path field tends to fill the majority of the file display border and the colors let you see which side is source.

But I don't want it to mix. The "File display border" color lets me know which side is the source.

But the path field almost completely covers the file display border? (At least normally.) If it didn't mix you'd only see a bit of the color around the edges and under the handful of buttons at the sides.

I have lots of buttons in my Lister toolbar, so there's plenty of color to help me distinguish between source and destination. I would very much prefer the location bar background to be white. I understand color mixing as a default setting, but maybe you could make an option under Advanced settings to let us turn off mixing?