The black taken away: the blue is only arcs, and the middle is plain white.
Shapes that aren’t there
Neon disc
Is there a glowing blue disc in the middle, brighter than the white around it?
No: only the arcs of the rings are blue. The middle is the same white as the rest of the page.
Why? The blue arcs stop where a circle would be, so your brain guesses there’s a see-through blue disc lying over the rings, and fills it in with a glow. Dino Varin drew rings like these in 1971, when he first described neon colors.
Picture: Drawn by Science Playground, after Dino Varin · Wikipedia(opens in a new tab)