Grey<br>I went to the store to buy a new phone. The one I wanted was available. The salesperson showed me three different colors. I had a hard time choosing. I finally decided on the grey model.
They bought the grey model, but didn't deliberate for very long. 
From the context we can see that they did deliberate for a while because it states they had a hard time choosing. The system likely could not equate hard time choosing with a long deliberation. 
( z0 buy :ARG0 ( z1 they ) :ARG1 ( z2 model :ARG1-of ( z3 gray ) ) :concession ( z4 deliberate :ARG0 z1 :ARG1-of ( z5 long :degree ( z6 very ) ) :polarity - ) )
(z0 / buy-01
    :ARG0 (z1 / they)
    :ARG1 (z2 / model
              :ARG1-of (z3 / gray-02))
    :concession (z4 / deliberate-01
                    :ARG0 z1
                    :ARG1-of (z5 / long-03
                                 :degree (z6 / very))
                    :polarity -))
They bought the grey model , but did n't deliberate for very long .
z0 :ARG0 z1
z2 :ARG1-of z3
z0 :ARG1 z2
z4 :polarity 0
z0 :concession z4
z4 :ARG0 z1
z5 :degree z6
z4 :ARG1-of z5