Isn't Mars beautiful in the summer? This is an official European Space Agency picture.
Here is original link. The image is actually very large. You might want to go to the ESA website for a clearer view of what is going on, here. To be fair, the ESA says these are sulfate deposits ... but why Lowell saw them shift with the seasons is another happy little investigation, and honestly, I like my imagination, better. This does look an awful lot like a forest ...
Of course, we've always known that Mars has blue skies. I had a picture here, but apparently the site is down, and I would just prefer you go to Kieth Laney's site, directly, anyway.
Here are some more links that you might find valuable:
The Hidden Colors of Mars.
Beautiful pictures of the real Mars ... with blue skies, and a little information you may find interesting.
Trees and Vegetation on Mars, More Images.
This is the original article where the above picture was linked from. All pictures are linked from the ESA ... because, of course, everything really good seems to still come from Europe.
Keith Laney's Mars Photography Website.
Color calibrated collection of photos from the Mars landers.