Just like many other authors, Ayn Rand uses color to suggest to the mind images for the reader to understand. There are colors that are associated with seasons, for example. If an author describes the setting where the trees have red and yellow leaves, then the reader can know that the time is set in autumn without the author explicitly saying so. Literary devices such as these entice the reader to participate in the story by interpreting the author's descriptive language. One of the first colors that Rand uses in Anthem is black, as in the following passage:
"The walls are cracked and water runs upon them in thin threads without sound, black and glistening as blood" (18).
Equality 7-2521 is writing in the tunnel that he found and describes the walls in an interesting way. At this point in the story he is desperate for knowledge and fulfillment. He lives in a society that is dark intellectually, but also generally because they only have candles and no electric lights. Life for him is dark and frustrating and so the character associates the water running down the walls as having dark qualities such as "black" and "glistening as blood".
Another example of Rand's use of color is when Equality describes the carved out words over the Palace of the World Council, as follows:
"These words were cut long ago. There is green mould in the grooves of the letters and yellow streaks on the marble, which come from more years than men could count" (19).
The green mold symbolizes that no one has bothered to clean up the exterior of the building, or they simply don't have the resources to do so. Both the yellowing marble and the green mold also symbolize age--that this society has existed for a very long time. These are simple devices used to give added hints to the reader as to the characteristics of the community.
Another color associated with the community is within the sleeping halls. At least the place that Equality sleeps is clean. White can symbolize purity, but in this case, it symbolizes cleanliness and the demand for the citizens to be clean as well. That's not a bad thing, necessarily, but it also means that Equality's life does not have vibrant or happy colors. It's the absence of color in this case that symbolizes a bland, boring, and unfulfilling life.
Finally, and probably the most important color used in Anthem is gold. Out of all of the white (clean and boring), black, green, and yellow (dirty) colors, comes the most radiant one. Equality uses the word "golden" to identify with a woman he falls in love with. The golden images come from the first time he meets her, and with subsequent meetings, as follows:
"Their hair was golden as the sun; their hair flew in the wind, shining and wild, as if it defied men to restrain it" (39).
"The Golden One were kneeling alone at the moat which runs through the field. And the drops of water falling from their hands, as they raised the water to their lips, were like sparks of fire in the sun" (42)."
Golden is the color of his love's hair and the light of the sun associated with everything about her! Before meeting Liberty, Equality sought the light of knowledge; but now, he also seeks to have the light of love in his life and the color that represents that love is gold.