How to store data during a blender session

After some more discussion we now arrived at the following solution to my original problem: use a new class and put you data in a static variable.

For the coloring of meshes during an animation, this solution (in its simplest form) looks like this:

import bpy
from radthcolormesh.colormesh import ColorMesh
class CMStorage :
    colorMesh = ColorMesh()
   
def applyColor(scene) :
    CMStorage.colorMesh.colorMesh('Suzanne')
bpy.app.handlers.frame_change_pre.append(applyColor)

Which looks nice and simple and can be easily expanded.