1)Coulrs used to paint sky and water
Ultramarine blue
Medium Magenta
chrome yellow
Titanium White
2) For distant mountains
Purple +white
Ultramarine blue
Sap green
3) willow tree
Black, burnt umber +white for the tree trunk and branches
Burnt sienna, black, chrome yellow and white for the willow leaves
4) grass
Sap green, black, brilliant yellow green, white