The hue angle values reveal that the Mn4+and Si4+
co-doped Ce0.95Pr0.05O2 pigments lie in the brick red to darkbrown
region of the cylindrical color space (h8 = 0–35 for red
and 35–70 for orange). It is clear from the L*a*b* values of the
Ce0.95MxPr0.05xO2 (M = Mn, Si) pigments summarized in
Table 1 that the present values are significantly higher than
recently reported praseodymium doped ceria powders (5%
praseodymium doped CeO2: L* = 66; a* = 12; b* = 9.5),
synthesized by microwave-assisted hydrothermal route [6].