Near a threshold, ordinary rounding can turn a calculation display into a misleading claim. Comparing #777777 and #767676 on white shows why ContrastCheck separates the raw decision from the floored two-decimal presentation and why a copied status should retain the exact color inputs.
#777777 produces about 4.478:1
Use #777 as foreground and #FFF as background. The normalized foreground becomes #777777, its relative luminance is about 0.184475, and the raw ratio is about 4.47809. That is below 4.5, so AA normal and AAA large fail. The display floors to 4.47:1; it never rounds upward to a value that visually resembles a passing 4.5.
#767676 produces about 4.542:1
Change only the foreground to #767676. It is slightly darker, with relative luminance about 0.181164 and a raw ratio about 4.54222. It therefore passes the 4.5 references, while the displayed 4.54:1 remains conservative. Both grays pass the 3:1 rows and both fail AAA normal 7:1, demonstrating that pass or fail always belongs to a named threshold.
Treat the minimum as a boundary, not a design target
A tiny channel change can cross the arithmetic threshold, but real interfaces also face font rendering, states, overlays and varying displays. Avoid choosing the nearest passing gray merely to satisfy a calculator. Preserve reasonable margin where the visual system allows it, test the rendered component and review every applicable pair. The example explains threshold mechanics; it does not prescribe a universal design color.