The Book of Zohar, Chapter “Truma (Donation),” Item 431: Black is very dark. Its color is not seen out of the darkness. Where was this color black and darkness dyed? When this red melted into the azure and the colors red and azure mingled, the fusion of filth from Midat ha Din melted into the deeps, Malchut de Malchut, and mire and sludge were made from there, as it is written, “And its waters toss up mire and sludge.”
The Zohar explains which quality, which Sefira each color corresponds to. Naturally, everything originates from Malchut and is perceived in it: We observe all the qualities from within Malchut. There are 9 Sefirot before Malchut, which are the Creator’s qualities, the qualities of bestowal. But when Malchut receives them and begins to work with them, they take on various shades in her to the extent of her ability to be on the degree of bestowal, from Keter to Yesod.
From the 2nd part of the Daily Kabbalah Lesson 7/7/2011, The Zohar