I’d go for a midnight blue base, like the deep dark between stars, then layer a swirling teal and violet gradient to hint at the energy of a wormhole. A soft, spiral shape that looks like a subtle torus, almost invisible at first but revealed when you zoom in—like a cosmic ribbon. A tiny silver fleck for a distant star, giving it that tiny spark of mystery. It keeps the design cool and reflective, but still feels alive.