Can I remove colors applied to a topographical map?

Question

For a project involving a client-supplied map (clip below) I need to be able to turn colored layers on and off. The client, however, supplied a flat image and vector outlines for the color regions, apparently all they can find. This is not the same as a layered image of course.

Is there some way I could remove the colors (and glow effects at boundaries) shown below while preserving the topography, and then reapply them using the vectors? Or do I need to go back to the client and ask them to keep digging for assets?

Thank you.

Answer 1

If both the color and the topography are on a single layer in Photoshop, or a single rasterized object in Illustrator, there is no automatic way to separate them.
Hopefully your client can find a file of just the topography, or you could try to find a third-party map vendor to purchase a topographical map of the area - it shouldn't be too hard to scale and align the vector objects you have to a new map, and then color as you see fit.

Answer 2

Instead of trying to show and hide color from the maps, use the supplied vector plots to create Hue/Saturation adjust layers.

These layers will have zero saturation (therefore making the maps grayscale) when the layers are turned on. If you want to see a color, turn the mask off. You will then see the original color.

You will have to do a couple more masks, such as brightness/contrast, to make sure the grays are all the same value.