The grass is not a deep green to begin with. As you have noted, it looks like it is water stressed but the truth is that it is fert stressed. Green it up and if you still have not achieved the desired results, use a real striper, like a Big League Lawns roller (heavy) or something like that. 90% of the stripes I see here at Lawnsite are more like just tire marks with very little striping effect. I do get decent stripes on Southern grasses but it's because I use a roller.
Serving Greenville, Winterville and Ayden NC