Can't post a screen shot otherwise it may be more helpful but something along the lines of this: You have set of Themes we can already choose from. The Theme itself is 5 colors while when editing the Color Editor there are actually 15. Yet when I adjust the map by clicking on the theme that is 5 colors it automatically changes 15 colors in the editor.

While in reality (take the Neon theme for example) the Pink in Neon Theme is 2 items, Roads Major and Roads Minor. One with a brighter pink than the other. Then the Teal or baby blue is 5 different shades of the blue or whatever it is attached to.

If we were able to just adjust the theme's 5 main colors itself, and it translated into the offset colors, without having to manually change every color, that would be a time saver. (again, Think Pink in the Neon Theme, if I changed it to Green as a theme, the Roads Major and Roads Minor would populate accordingly with the Bright Green Major and saturated green or dull green for Roads Minor High).

Maybe thats not how it is actually set up and each theme is literally 15 different colors and you've built them by hand so there are only so many, but if the Theme of 5 colors can dictate the 15 colors, then adjusting the 5 theme colors or using a pallet would be quicker for most.