A man in a gray shirt playing a whistle.
a man in gray trousers and a hat plays a whistle
Trousers are available in different colors besides gray.  Not all men wear hats.
exists e1 s1 x1 x2 x3 x4.(a_topic(x1) & in(x1,x2) & Theme(e1,x4) & Actor(e1,x3) & v_play(e1) & n_whistle(x4) & (x2 = x3) & n_shirt(x2) & a_gray(s1) & Theme(s1,x2) & n_man(x1))
exists e1 s1 x1 x2 x3 x4 x5.(Theme(e1,x5) & Actor(e1,x1) & v_play(e1) & n_whistle(x5) & subset_of(x4,x1) & n_hat(x4) & subset_of(x2,x1) & in(x2,x3) & n_trousers(x3) & a_gray(s1) & Theme(s1,x3) & n_man(x2))