HIFIFAST YELLOW HF4G-LB (Pigment Yellow 151) is a greenish yellow pigment with excellent fastness to light and weathering, especially in deep shades. It has relatively good opacity for an organic pigment. As it has very good flow properties in paints, it can also be used at high pigment concentrations without affecting the gloss. It should be borne in mind that the resistance to very strong alkalis is unsatisfactory.