Create a finished [Aspect Ratio] abstract exhibition post...

Create a finished [Aspect Ratio] abstract exhibition poster, flat matte spot-color print. One dense motif zone fills about half the poster: broad heavy flowing bands packed almost edge to edge, rounded elbows, one integrated half-disc, and a short bundle of fine ivory lines cut through one thick band. The other half is open warm ivory paper (#F5F0DF). Motif: [Motif] Inks: [Inks], plus navy #143A59 for all type. Library: green #17613C, lemon #DDEB34, vermilion #E94F31. Use one or two of them, never all. Title "[Title]" in large navy upright neo-grotesk caps, subtitle "[Subtitle]" smaller and lowercase beneath it, set in the open paper. Clean flat color only: no shadows, gradients, grain, texture, logos or small icons.