Commercially available spinel cobalt blue (CoAlO) utilizes a significant amount of carcinogenic Co, which makes its synthesis more hazardous and environmentally harmful. Considerable effort has been put into developing more environmentally benign and robust blue pigments to replace cobalt blue. A new class of blue pigments with tunable hue were prepared. The solid solution series, CaAl Co Ti O (0 < ≤ 1), crystallizes in a hexagonal mineral hibonite (CaMO) structure with five distinct crystallographic sites for M cations (M = Al, Co, and Ti). The origin of intense blue color is attributed to a synergistic effect of allowed transitions involving the chromophore Co in both tetrahedral and trigonal bipyramidal crystal fields. Compared with commercial cobalt blue, these tunable hibonite blues possess a reddish hue that intensifies the blue color as observed in Y(In,Mn)O (YInMn) blues, with a significant reduction of Co concentration from 33% to as low as 4% by mass. A significant advantage of hibonite blues over cobalt blue is the substantial reduction in carcinogenic cobalt content while enhancing the color properties at a reduced cost for raw materials.