We're going to start with this landscape shot as our original image. Let's go ahead and go to Object>Rasterize to rasterize it.

Now let's apply an image trace onto the photo. Set to 16 colors, this will separate out the contents of the photo into 16 distinct color regions. Expanding this will then allow us to access the individual vectored sections.

Our next step is to use the recolor option to...well...recolor it. Remember to uncheck the lock button if you want to explore a wider range of color themes. 

Looking at some references, summer tones tend to shift to more vibrant green tones and blue colors get shifted to a much warmer tone. Everything with the colors here dedicate themselves to the intensity of the light that comes with the season. 

Autumn is defined by orange leaves, translucent yellows mixed into the environment, and pale blues. So let's try to implement that into this scene. I like to emphasize the rainy and dimmer skies of autumn by keeping things a little desaturated, but given the sunset setting, we can't go down too far without revoking the energy of the light from the scene. 

Here we have a winter version. Winter in most lighting has that normal desaturated look that Fall does. But, winter has the addition of snow and frost which amplifies the brightness of the scene and stretches the effects that light would have on every terrain. Reflectivity of the sun's rays also creates very striking warm tones in the context of all this white and blue. 

Before we submit our final versions, let's touch up that summer one. I think it needs to be brighter and have some more saturated colors.