That they do demonstrate. With this Plasma wallpaper it does look good, since it's colours are darker and there's no overlapping elements in the background. But this changes if the next release's wallpaper have more "stuff" and brighter, more vibrant colours, unsless this taken into account when designing it.

An alternative would be to "adjust" the colour from the bright blue to a more neutral colour. Looking to e.g. Mac OS, you have a very pleasant grey colour, is the same I have set on my KDE desktop.