Answer

It is described in detail as ‘blue’ he sees the ‘fishermen pushing (their boat) out to sea’ and there are other colours and sensory experiences such as:

the sun ‘surfacing defiantly’: the personification of the sun makes it more powerful and energetic

‘the small emerald island’ makes the island more valuable to him as it is like a jewel made of emerald to him. It also expresses the green lusciousness of the grass and the landscape.