Wrapping on noncylindrical shape

Here is a drawing I have.  It is a complex shape of a lampshade.

My friend who is an artist wants to do the following

Scan a shape: a leaf, a flower, whatever

Do "color separation" in the editing program to get two or three colors for the object

Get an appropriate import file (e.g., dwg, dxf, whatever) or set of color-separation import files

Import the file(s)

Wrap the image(s) onto the interior of this shade

Extrude them inwards

The shades will be printed in a white, somewhat translucent color

We have a 4-filament 3D printer (Prusa XL.  At least, we hope to have it by the end of June).  The extrusions may print in one color of filament, or we can have three other filaments plus the base white

The goal is that when the light is turned on (a LED light, so it will not melt the plastic) the designs will show through.

The color filaments will be translucent colors.

This may not be possible in the current program because of wrap being limited to cylinders.

One interesting idea is to not wrap it, but put a vertical plane through the center.  Put the image on the plane.  Extrude it to the surface.  This will make a big, solid chunk of color.

Shell the color.  This may require extruding symmetrically to opposite sides so the shelling works.  Fine.  Limits us to having things essentially mirrored.  Not an artistic crisis.

For color separations, extrude one color, then suppress it so we can extrude the next color, and so on.  Then, having shelled the blocks, unsuppress all the suppressed extrusions,  run it through the slicer, and print it with up to four colors (up to three colors plus base shade).

Any suggestions, perhaps a better way to do it than what I am suggesting?

EDIT: I tried the above idea.  It is very difficult.  The current drawing puts a "pentahex" figure in the center plane.  The problem goes like this:

I have to first extrude the outermost object (the hexagon).  Then I shell it and remove seven of its eight sides.  Well, there's the problem.  I have to remove 12 of its 14 sides.  What?  Well, when I "shell" it I get an internal pentagon shell on the inside.  Locating and eliminating these sides is really hard, because there is no way to 'reach inside' of an object to 'name' some enclosed surface.  Lots of manipulation, and if I didn't have that hole in the bottom to fit over the bulb I would have no chance.  But I'm finally left with just one side, the side against the shade, a hexagon shape with a pentagon hole in it.  Whew!  I can't imagine doing this with an artistic shape!  Then I extrude the pentagon, shell it, and remove 6 of its 7 sides, and I'm left the the pentagon.  I made the shells 1/10 inch thick so they show; in the final product the shells may be significantly thinner, perhaps 1/32 of an inch.  So it seems to work, but it is clumsy to use, and I should have done it as a derivation of the basic lampshade, but I was experimenting.  Will fix that, but it's 3am, I've got a morning dentist appointment, and it's time to go to bed.