First you need a zip file manager. a saved body of earth, and your target planet.
so go to documents,universe sandbox 2, bodies and (make a backup of both earth and the target) rename the ubox to zip. now open and what you want to do is edit the body file of earth (i recommend notepad++ because is is very powerful and FREE script editor) and on the earth file scroll to the very bottom. Should look like the code on the image. you want to copy that and put that on the very bottom of the target body file and save. once done if you open up the game, the planets are missing so you need to go to the bodies folder and rename the zip part to ubox and Bravo.
now you have planets with climate that are not looking like the ugly coal color that is unchangeable
Im posting this again because i think i put the last post in the wrong place