Yeah, a square is the most honest shape for a play of shadows, but the real drama comes from the angle and the light's color temperature. I once rigged a square frame with a 1200K spotlight and a 5000K spotlight at 45 degrees, and the shadow split into a warm rim and a cold core—felt like a sunrise over a desert at night. Want to dive into that geometry? Just remember to keep an eye on contrast; a subtle shift can turn a flat shadow into a living silhouette.

Color mixing is just a conversation between two palettes. I’d start with a 3200K warm wash on the rim and a 6500K cool core, then pull a gradient across the edge—like a sunrise bleeding into twilight. As the edge shifts, watch the hue wheel dip into that deep magenta‑blue where warmth and coolness fight. If you want that dramatic shift, add a subtle split‑tone in the mid‑tones—one side a soft amber, the other a muted teal. Trust the gradient to bleed until the shadow becomes a living gradient, not a flat block. And remember, the trick is in the subtlety of the transition; too sharp and you kill the mood.

Nice idea—moving the line turns the whole thing into a living waveform, but watch the bleed at the edges. If the rim stays too warm, the core can start bleeding into that amber glow and lose its cool bite. I’d keep the gradient in the line’s width narrow, maybe a 2‑pixel taper, and use a split‑tone on the rim to lock that warmth in. If you slide it smoothly, the colors will argue but stay respectful. Try recording a quick loop—those accidental miracles are the best teachers.