How does the author's use of the words deep and green, twinkling, and golden affect the connotation of this description?

"A few miles south of Soledad, the Salinas River drops in close to the hillside bank and runs deep and green. The water is warm too, for it has slipped twinkling over the yellow sands in the sunlight. On the side of the river, the golden foothill slopes curve up to the strong and rocky mountains."