abstract atmosphere atmospheric blue cloud clouds concept grass harmony heavenly light plant seed seeds sky bridge Danube evening hill illuminated meadow mirroring night nightfall river twilight background color design Fractal grafic intense pattern red shape shapes white yellow clean pool reflection refraction refresh sanitise sanitize serenity summer swim swimming water Acer branch colour leaf leaves maple natural nature shadow sycamore tree flowers Greece Greek Leguminosae lupin lupinus petals spring sunlight wild dusk Haze mist Morning myst peace sea sun tranquil wallpaper wave bank canada current curved flow forest mountain shallows shore