A “Sefirat HaOmer” chart by Aharon Varady in the design of Lauren Deutsch, following the color correspondences of Rabbi Zalman Schachter-Shalomi, z”l. Each of the seven weeks and days of the Omer is represented by one of the seven lower Sephirot: Ḥesed, Gevurah, Tiferet, Netzaḥ, Hod, Yesod, and Malkhut, the creative emanations all the worlds were created and continually sustained, as taught in the Kabbalistic tradition. The first day of the Omer at the top left signifies “Ḥesed within Ḥesed.” The circle below representing the second day signifies “Gevurah within in Hesed,” and so forth. The forty-second circle on the bottom row marks the 42nd day of the Omer, Yom Keshet, Rainbow Day, which is “Malkhut that is in Yesod.

http://opensiddur.org/earth-cycle/seasons/spring/סדר-ספירת-העומר-the-order-of-counting-the-omer-in-the-spring/