Disclosed are compositions, such as inkjet inks, for jetting onto a ceramic substrate, and associated methods and systems. The compositions comprise a pigment compound that is configured to be jetted on a ceramic substrate during a ceramic inkjet process to impart a color effect to the ceramic substrate, and a reduction agent which, when exposed to a firing temperature, reacts with the pigment compound to cause a reduction reaction. In some embodiments, the pigment compound comprises jettable copper particles, which can cause the fired composition to take on a red or oxblood color, which can be used for decoration.