Old Masters Palette:

Peter Paul Rubens (1577–1640)

Jacques Maroger claims that Rubens limited his colors to little more than yellow, brown, black, white and red. He states, "But from a distance, one has the illusion of perceiving blues, greens, violets... The greatest colorists have always obtained the maximum brilliance and vibration with a minimum of colors."

True as the latter part of his statement may be, it is doubtful that Rubens' palette consisted only of these colors. According to Hilaire Hiler, a study of the pigments found in a trunk from Rubens' studio, now preserved in the Antwerp Museum (presumably this is now the Koninklijk Museum voor Schone Kunsten Antwerpen or Royal Museum of Fine Arts in Antwerp), reveals the following:

In the 1620s Rubens paid 45 guilders for an ounce of ultramarine blue.

It is most probable that Rubens did not use all of these colors at any one time.

The technical ability of such artists as Rubens and Rembrandt to obtain a wide spectrum of colors from a limited palette through mixtures of pigments is nothing short of amazing. For example, Rubens used a technique to obtain a violet or purple color, a pigment that did not exist in his time, making a bluish tone by mixing wood charcoal with lead white and together with madder lake or cochineal lake creating the desired violet or purple color.

In his book, Hiler further repeats the text from Vibert: "There is a trunk in the Museum, at Antwerp, which contains the powdered colours used by Rubens. The lead white, the ultramarine, the madders, and the earth colours are in a good state of preservation, but the yellow lake, the vermilion, and the vegetable greens have faded almost entirely faded away."

Interestingly, Vibert's account differs in the present state of these pigments: "White lead, cinnabar (native vermilion), lapis, charcoals, madder lakes, earths and ochres have resisted very well; but buckthorn, like all yellows, reds and vegetable greens, has more or less disappeared."

The tapestry industry used wools and silks dyed in the following colors: are madder, cochineal, blue vitriol, gall nuts, alum, tartar, indigo, orseille, bois jaune (fustic or mulberry wood).

Notes
* Faber Birren repeats the list in Hilaire Hiler: They both list "Azur d'Allemagne" as cobalt and "vert azur" as cobalt oxide in Rubens' palette. We are not certain why Hiler associates these names with cobalt pigments.

Azur d'Allemagne (literally, blue from Germany) is a name usually applied to the mineral azurite. However, one Internet reference identifies it as a synthetic pigment made from Saxony cobalt ore.

Vert azur (literally, green blue) may refer to malachite or verdigris. Azurite, malachite and verdigris are copper pigments and do not consist of cobalt.

** Although genuine ivory black was available in Rubens' time, wood and bone charcoal were more common. Recent papers on the subject of black pigments shows that artists of this period made extensive use of many different black pigments, such as coal, black iron oxide (magnetite), and chimney soot etc.

References
Jacques Maroger (1942). The Secret Formulas and Techniques of the Masters. New York: Studio Publications.

http://www.naturalpigments.com/vb/content.php/133-Old-Masters-Palette-Rubensrxr