I used the same colours for the grass - cobalt blue and aureolin yellow, but I changed the colour scheme for the sky quite a bit: raw sienna, ultramarine, cerulean, indigo. And for the tree line, well, a mix of everything, with some transparent orange and red madder too.
I love how this painting has worked out so far (afraid to jinx it by saying that!)
I still have to do the lampposts. I'm exploring a different technique for these. This painting is about A4 in size, but I'm planning to go big again.