I'm trying to create my very first theme. I'm going for a dark purple color scheme. However, I can't figure out why this lighter dark purple is showing below the last file but not under the filename column. I'm in regular Details view. I don't want the lighter dark purple. I want the darker dark purple.
My guess is you have set the sort column to black, and the background color for unselected files to black, but you've set the file display background to the lighter purple.
If you don't want something to use a special background color, set it to transparent (or turn it off entirely, if it's the sort column) instead of to black (or whatever). Then define the color you want for the background as the actual file display background color.
If something has a transparent background, the file display's background color will be behind it. That's also the color used for areas that don't have anything over them at all, like the bottom-right of your screenshot.
Ahh! That's much better...although I had to darken my background. It's looking spiffy now!