I always enjoy teaching warm and cool colours and I think my grade ones did a great job with this lesson which is courtesy of 'Color Like You Mean It'.
I had my students begin with a "wavy" line across the middle of their page to represent the sea. They then drew a semi circle for the sun (those who would struggle with this were given a paper plate to assist them to draw the shape) and added lines for the rays of the sun (yes, this is the only time this is OK!). I then asked them to practice their best wavy lines to draw in the ocean waves and those who needed more of a challenge could draw spirals too. We outlined in black permanent marker before painting in watercolours. Students were encouraged to mix their own colours as well as using the ones available.