Kortog was home to Stratus City, which was a city that was suspended high above the planet. It was part of Tachyon's empire and used to be the Educational District of the Polaris Galaxy before Tachyon invaded. After the battle of Fastoon and Tachyon's rise to power, Kortog became the Cerullean Sector capital. This was where Clank got an upgrade from the Zoni called the Robo-Wings. The city was full of Robo-Wing launchers that the player could use to fly anywhere in the city. If you go on all of them, you get a skill point.
The otherwise reddish color was probably let off by the number of red colored architecture throughout the planet, along with amount of red-colored gases seen throughout the cities.
This planet was the first planet in the game which had the RYNO IV plan, and in order to reach this plan, one had to get the Robo-Wings. There was also a secret passageway under a staircase that lead to a Raritanium chest.