I use (set-face-background hl-line-face "gray13").
here’s what it looks like with a black background.
Very subtle. Mostly I notice it when moving the cursor, which is what I wanted.
If you want to see a display of all the various colors, try (list-colors-display). It will show a list of colors in a new buffer.
EDIT: heh heh, since I am getting upvoted for pretty pictures,
here it is “live”:
(ps: that animated gif was produced with the Cropper tool and the AnimatedGif plugin.)