Original PickImageColors source-file lab, 2026-10-25.
When can a picked HEX code be shortened to three digits?
Run: python reproduce.py --case exact-three-digit-hex --out rerun
Dependency: Pillow. Recorded runtime: Python 3.12.14, Pillow 12.3.0, libwebp 1.6.0.
Measurements are local source-file computations, not browser observations. Library-dependent compression sizes and quantizer choices may change with runtime.
We tested six-digit opaque RGB and its exact three-digit CSS representation. Alpha shorthand and perceptual nearest-color selection are separate questions. A shorter notation does not promise a visibly equivalent result when digits were discarded.
