try right click the one set and choose edit. when its displayed for editing go to load color set icon and when prompted choose append the second color set then save the two with a new name-under save as . can then save form and pick this up when need to use it. 

I don't seam to find the go to load color set icon on the display for editing. I find this when I am creating a plot and in the legend I want to display multiple colour sets.

Open the M13 to M24 colour set.  Select all the cells and press Ctrl+C to copy to clipboard.  Open M01 to M12, append a row and Ctrl+V to Paste.  Then Save As M01 to M24.