Teenage Engineering's OP-1 is a CNC-machined, powder-coated aluminium synthesizer whose entire body — housing, keys, and knobs — is a single cool light grey. The only saturated color comes from four rotary encoder caps in blue, green, orange, and white.

This design system translates that hardware logic to screen: a uniform machined-grey ground, technical monospace labels in uppercase, fine seams and precise small radii, with color reserved strictly for tiny instrument-panel dots.