Niddah - Color Chart

According to the Mishnah (Niddah 2:6) and subsequent halachic discussions, only certain shades — primarily those resembling the colors of blood from specific sources — render a woman niddah .

Default to chumra (stringency) if it’s ambiguous, but ask a rabbi. Many shades of brown are considered tahor unless they clearly tend toward red. niddah color chart

The chart is a reference of standardized colors, traditionally ranging from deep red to pale yellow or beige. It allows a woman (or a posek, halachic authority) to determine whether a stain found on a bedikah cloth (examination cloth), undergarment, or other surface is tamei (ritually impure) or tahor (ritually pure). According to the Mishnah (Niddah 2:6) and subsequent

No. Halachic charts are calibrated according to Talmudic descriptions. Use one endorsed by a recognized posek or organization (e.g., the Kehati chart, Bedikat HaMishpacha chart). The chart is a reference of standardized colors,

Some contemporary poskim permit high-quality color printing or apps, provided they are tested against a master original. However, screen variation makes most smartphone-based charts unreliable. Stick to physical strips kept in good condition (not faded).