Mishnah for Negaim 2:1
בַּהֶרֶת עַזָּה נִרְאֵית בַּגֶּרְמָנִי כֵּהָה, וְהַכֵּהָה בַכּוּשִׁי עַזָּה. רַבִּי יִשְׁמָעֵאל אוֹמֵר, בְּנֵי יִשְׂרָאֵל, אֲנִי כַפָּרָתָן, הֲרֵי הֵן כְּאֶשְׁכְּרוֹעַ, לֹא שְׁחוֹרִים וְלֹא לְבָנִים, אֶלָּא בֵינוֹנִיִּים. רַבִּי עֲקִיבָא אוֹמֵר, יֵשׁ לַצַּיָּרִים סַמְמָנִין שֶׁהֵן צָרִין צוּרוֹת שְׁחוֹרוֹת, לְבָנוֹת וּבֵינוֹנִיּוֹת. מֵבִיא סַם בֵּינוֹנִי וּמַקִּיפוֹ מִבַּחוּץ, וְתֵרָאֶה בַבֵּינוֹנִי. רַבִּי יְהוּדָה אוֹמֵר, מַרְאוֹת נְגָעִים לְהָקֵל אֲבָל לֹא לְהַחְמִיר, יֵרָאֶה הַגֶּרְמָנִי בִּבְשָׂרוֹ לְהָקֵל, וְהַכּוּשִׁי בַּבֵּינוֹנִי לְהָקֵל. וַחֲכָמִים אוֹמְרִים, זֶה וָזֶה בַּבֵּינוֹנִי:
A bright <i>Baheret</i> [type of diseased patch that creates impurity] looks dull on a light-skinned person [lit. German] and a dull one looks bright on a dark-skinned person [lit. Ethiopian]. Rabbi Yishmael says: Bnei Yisrael, may I am be their atonement, behold they are like box-wood, not black and not white, but intermediate. Rabbi Akiva says: Painters have pigments with which they paint forms black or white or intermediate. One brings an intermediate pigment and surrounds it [the <i>Nega</i>] from outside, and it will appear in the intermediate. Rabbi Yehudah says: The appearances of <i>Negaim</i> [diseased patches on skin, clothes, or houses that create impurity, should be decided] for leniency [when in doubt] but not for stringency: he [the examining priest] should look at the light-skinned person in [comparison with] his skin for leniency and the dark-skinned person in [comparison with] intermediate [dye] for leniency. The Sages say: Both this and this [case should be looked at in comparison with] intermediate [dye].