Upvote:9
It appears the consensus is indicating multiple colors.
In Mesopotamia the seven stages of a ziggurat were each painted a different color, the colors being emblematic of the seven planets Handc**k Mesopotamian Archaeology p 273
The above quote from a book in 1922, and it appears to be quoting another source on Mesopotamia by Hanc**k.
Another source discussing the ziggurat says:
The ziggurat consists of several terraces made of bricks on the top of which a small chapel was erected open in front with an altar before it The chapel contained the image of the god sometimes the walls of the terraces were made of enameled bricks in different colors black white purple blue red silver and gold
A more recent source, Ancient Mesopotamia: New Perspectives By Jane McIntosh, has a different color list claiming the colors are Black, White, Red, Blue, Orange, Silver and Gold.
So some form of these may be your actual color combinations. One more source seems to identify again the astronomical implications of the colors:
The seven stages equally high and each one smaller in area than the one below it were covered with stucco of various colors thus exhibiting to view the colors consecrated to the seven great celestial bodies the least important being at the base This tower was the ziggurat or observatory on whose summit the priestly disciples of the Chaldaeans endeavored to divine the future in the stars.
Illustrated History of All Nations: Containing a Record of the ..., Volume 1 By Israel Smith Clare