We have to change now the colors' corrections to create the necessary atmosphere, an evening one. First make the necessary corrections on the sand' layer, using the next options: Image ? Adjustments ? Curves (ctrl+m) and Image ? Adjustments ? Selective Color.





Then continue with the castle's layer, applying the same options:

 




Insert now a small shadow coming from the sand' layer. First we need to copy the layer: Layer ? Duplicate Layer (ctrl+j) and make it totally black with Image ? Adjustments ? Channel Mixer:



Then blur out the layer, making use of Filter ? Blur ? Gaussian Blur.