The file that contains to hues to be copied is the read file.
The file that will be copied to is the destination file.
Enter the read code and write code in the boxes in hex format 
and press Transfer to copy the color.

When you are done copying hues press the "Write new file" button
to create the new hues file.  The new file will be named "newhues.mul"
and will be located in the same directory as the destination file.

Note:

If you are using InsideUO to view the hues the indexes are off by 2.
If you are using UOHueEditor the indexes are off by 1.