1. Hazy Summer - is meant to be the top right one and is the lab curve A.

The tonal contrast has not been changed in the L channel, but the two colour channels have been steepened to give some saturation and the warm end slightly changed and the green grass slightly de-saturated

2. Late afternoon - bottom left and is the other lab curve C

A Shadow point was set (in the L channel) and then further darkened to give a very steep curve for the grass hills, which was pegged so as not to blow the sky.  This time just the warm colours (+ve values in the a and b channels) were saturated.

3. High Altitude - bottom right with the magenta cast, is rgb curve B

The colours have increased a little because the Shadow point was set, which made each of the channel curves steeper. The Blue channel was tweaked to fade the grass in the foreground and accentuate it around the rocks.  The master rgb curve was lowered to darken the shadows and kinked at the top to make the sky more blue.