Yes kiltmakers here have explained that they need a single line that's flanked by plain stripes wide enough so that unwanted areas don't peek in, where the pleats get a bit wider due to the flair.

The military Black Watch-based tartans are ideal for that.

BTW if I recall correctly from seeing the House Of Edgar swatch-books the "background" dark blue and dark green used in their Modern range isn't as dark as I've seen in other fabrics. I've seen some tartan where the blue and green are extremely dark.