「Mars」一字是現今對合成氧化鐵顏料的通名。其顏色是由含水的鐵氧化物，運用石灰或者是碳酸鉀共同沈澱所製成。此一混合物的比例控制了顏色的色度，若將成品晾乾，就會產生合成氧化鐵黃，其他顏色則包含橘色、紅色、黑色、棕色，以及將黃色鈣化所產生出的紫色。「Mars」一字原本是西元十八世紀晚期的一個品牌名稱。"Mars" is now the common name used for synthetic iron oxide pigments. Mars colors are made from hydrated iron oxide co-precipitated with alum using lime or potash. The proportion of the mixture controls the degree of color; drying the product produces Mars yellow, other colors include orange, red, black, brown, and violet, produced by calcining the yellow. "Mars" was originally a brand name in the late 18th century.