Original PickImageColors source-file lab, 2026-10-25.
Where does alpha go in an eight-digit CSS HEX code?
Run: python reproduce.py --case css-eight-digit-hex-alpha --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.
This is source-byte serialization and parsing, not a browser rendering test or a new export feature in the picker. Apparent appearance also depends on the background. We do not describe alpha 128 as an exactly half-opacity value.
