Currently, if you have the panel on the bottom or the sides the accent bar is moved to the very edge of the screen. (bottom is on the bottom, left is on the left, right is on the right) However, if you were to put the panel on top the accent bar is kept at the bottom and not moved to the top of the screen. It would be for consistent if it kept the behavior as all other panel locations where the accent is on the edge of the screen. Furthermore, the accent color would not clash with the user's wallpaper or current app unlike the solid white/black panel color.