Advancing art class: 2 color studies

Once the value study was done I started working on a palette for the painting.  I refer to the figurative 'palette',  the range of colors used in a painting.  To help me decide I did three additional sketches using sightly different set of pigments.

I also used these sketches to work out a few additional problems.  The castle should be the center of interest but it is fading into the mist.  The rocks in the foreground have a lighter value, but if they are too light or distinct they become too interesting.

There are several shades of green, yellow and brown that are very different, but still need to fit together.  What shade makes the grass look like grass, but doesn't make it standout?   Does adding brown to the castle bring it out?

The bridge is the darkest object in the sketches and so it draws attention, but it also leads the eye to the castle.  Will adding purple to the deepest shadows add depth to the bridge or make it too dark?  Will adding purple to the rocks in the foreground help them fade?

Doing multiple sketches is more productive if you use tracing or graphite paper to transfer a single sketch multiple times.  The first two sketches used a transfer of the same pencil sketch as I used for the value sketch.  For the third sketch I used a different transfer, in which the castle is a bit smaller and there are more rocks and wrack in the foreground.  The third sketch is the one that most people have liked the best.

The pigments and mixes used can be seen as small dabs to the right of each sketch, and are in order: 

1. Ultramarine Blue, Yellow Ochre, Sap Green
2. Yellow Ochre, Burnt Sienna, Ultramarine Blue,  Sap Green, Dioxide Purple, Cadmium Light Green
3. Yellow Ochre, Sap Green, Cobalt Blue, Dioxide Purple