Memory reqs of an SVG?

[John]

On the train into work this morning, I was working on a project idea.  The idea is a multi-layered map in SVG for a wargame.  Now, the various layers are primarily meant for segregation of data, by purpose, in memory.  For instance, a height map layer that contains data showing topographic heights; another map that dictates foliage layer and density, etc.  The purpose of layering is to allow the map to toggle visibility of the layer (using <g> element grouping) and limit the amount of data that the engine will have to search to resolve a data check (so it only searches the Foliage layer, and not the height map, for foliage density checks).

Layers of Map
  Layer numbers are numbered from 0 upwards, so higher numbered layers are above, or painted later than, the lower numbered layers.
    
    #      Vis?     Usage and notes                                                                        Bits         Style
    0       Y       Topographic visual map                                                                  32           SVG
    1       N       Height map (256g)                                                                        8           BMP
    2       Y       Water visual map                                                                         8           SVG
    3       N       Water depth map (256g)      boolean subtracted from topographic height map               8           BMP
    4       Y       Manmade visual map          roads, buildings, bridges, constructions                     2           SVG
    5       Y       Foliage visual map                                                                       8           SVG
    6       N       Foliage depth map (256g)    boolean added to topographic height map                      8           BMP
    7       Y       Element plotting layer                                                                   8           SVG
    8       Y       Effects plotting layer      smoke, light                                                16           SVG ?
    9       Y       Overlay plotting layer      planning overlays                                            8           SVG
   10       Y       Grid lines                                                                               8           SVG

1920000 pixels in a 1600x1200 px map.  Since the some layers are SVG (text), they wont count pixel by pixel.

Now, my question is this:  For the SVG layers, does the color depth impact the memory requirements for that 'layer' at all?  Does Batik default all SVGs as a specific color depth (32-bit), or does it dynamically examine the data and use memory based on what it finds?

Would a black and white (2-bit) SVG of text take less memory than an identical 32-bit color SVG of the same node/shape/glyph data?