What you're looking at above is Blue Mars user DanielRavenNest in a Blue Mars that's decidedly red. That's because Daniel imported an actual topographic map of the planet into Blue Mars:
"It's the part of Mars that has the four large volcanoes," he tells me, "roughly what's in this photo." Daniel imported NASA satellite imagery of the Tharsis Montes area of Mars where Olympus Mons resides, which is about 2400 x 2400 kilometers, and scaled that down to fit into the Blue Mars terrain map, which is 8 x 8 km. As he explains, "You can import terrain maps (both height and color texture) into a Blue Mars city. They need to be greyscale and color bitmap (.bmp) files respectively, and the correct size... But you can import any real world map as a base for a Blue Mars city if you can get the data in the right format."
The final result of Daniel's world-making efforts can be seen in this video, a flyby in Blue Mars over red Mars mountains:
DanielRavenNest did this in Blue Mars' developer mode, so you can't visit it in-world, at least not now. Daniel (who's known as DanielRavenNest Noe in SL) tells me he might bring it into the several places he owns in Blue Mars: "I might resurrect it later on if my other cities fill up."