Tom, I take it that the grass had that parched-brown look in reality. I think it probably had as what green grass there is looks OK. The parched-brown bits, especially those areas near the sculpture have a slight hint of red but this may be the genuine colour. Often there is a redness in soil which film captures but our brains tend to filter it back to "brown" which is what we expect soil to be
I like this sculpture. The Park sounds like a quirky place