Disclosed is an ultraviolet-curable inkjet ink set composed of a yellow ink, a magenta ink and a cyan ink, respectively containing a pigment, a reactive monomer and/or a reactive oligomer and a photopolymerization initiator. This ultraviolet-curable inkjet ink set is characterized in that the yellow ink contains at least a bismuth vanadate compound or iron oxide, the magenta ink contains at least iron oxide or a condensed polycyclic compound and the cyan ink contains at least a phthalocyanine compound, as their respective pigments. Also disclosed is a colored board for outdoor use, which is printed by using the ink set. The inkjet ink set realizes high-concentration printing, and enables to obtain a brilliant printed matter excellent in color presentation and weather resistance.