Zechariah 6:2 Midrash

בַּמֶּרְכָּבָ֥ה הָרִֽאשֹׁנָ֖ה סוּסִ֣ים אֲדֻמִּ֑ים וּבַמֶּרְכָּבָ֥ה הַשֵּׁנִ֖ית סוּסִ֥ים שְׁחֹרִֽים׃

In the first chariot were red horses; and in the second chariot black horses;