as far as i know, you can not do such a thing. i'm sorry.
EDIT: level up.
I might put some sort of signature here once. I guess.
JeRRy86, you can. Okay, first, open up the OW in 2 seperate windows (one the OW you want the palette on, and the other w/ the palette you want) and open the palette editor on both. (Keep holding down ctrl all the time)Left click on the color you want to copy, and right click on where you want the color in the other ROM.
Edit: When I say keep holding down ctrl I mean when you're doing the left/right clicking, that may be a little confusing.
Wish there was an update to Lunar Magic in the future where you could copy a palette of an ow and put it into another hack via importing. (hopefully there will be)
Anyways, as far as IK the only way is to open both overworlds of both hacks and copying the values of colors onto the other hack.