BASF Turf Mark® 59013417 2.5 gal Blue Spray Pattern Indicator. Turf Mark Blue spray pattern indicator adds bright blue color to show exactly where fertilizer and pesticide applications have occurred. The highly visible color shows coverage and identifies drift, preventing skips and costly overlaps. The temporary color dissipates over time with sunlight and moisture for discreet applications. Turf Mark Blue spray indicator is formulated for mixing in boom, spot-gun, hand-held and other standard spray equipment. Turf Mark spray indicators are offered in a variety of convenient formulations. The WSP (water soluble packet) formulation is a premeasured, dry formula that disperses in the tank as it dissolves in the solution.