Variable color in SVG export

Question

Hello,
we are in the process of designing a website for one of our customer, with the goal of making them self-sufficient in feeding the site with new products.
One of the feature requires producing custom SVG files which are then rendered to PNG (when the browser doesn't support it correctly, that is most of them including Firefox which doesn't like gradients yet), and the possibility of updating several of the item colors on the fly.
This requires identifying in the source file which colors must be flagged as say, "variablecolor1", "variablecolor2" and so on, with XML entities or some other means.
Think about online visualization of t-shirt color changes.
It's not actually scripting-specific, but nor windows or mac, and maybe there is a scripting solution to it.
Since our customer is using Illustrator to generate their catalog, we wanted to integrate as much as possible with their workflow. AI seems to generate usable SVG files, however, we would like to avoid having to write an error-prone post-processing engine (likely in php) the designer will have to run to assertain which color entries in the files are the one we want to modify. Note possibly another part of the drawing with the same color might not be part of what to change...
A possible option would be creating the SVG with a predefined color, like #0000fe for variablecolor1 or whichever, but they want to have it look with the chosen default colors when not yet changed. Having them produce two versions (one with correct colors and one with hardcoded values for us) seems error prone.
The other option, as said is to run the SVG code through some magic identifying the color values, list them and allow checking which are to change. However this is also possibly error prone.
With a co-worker we checked AI for quite some hours without much luck trying to find something that would allow us to directly flag those colors. The online manual had topics with interesting names but the descriptions weren't really helpful, so we had to test on his machine.
We found about variables in AI, but sadly it seems this doesn't concern colors at all. Text, data and some other things but no color.
Some other palette-swapping functions didn't seem to pass anything when exporting to SVG.
Also, we checked the various option in the SVG export dialog, one exports XML entities, which would seem interesting if it didn't export the whole style of the object, besides it doesn't concern gradients which stay with their hardcoded colors on the gradient stops in the XML code.
I find it odd that no such feature exists to allow variable or named colors in drawing...
Does anyone know about such feature, or think it's possible to script something to easily flag the current object in such a way the SVG export would retain this information ?

Answer 1

Oh, BTW, it technically is not a white background either. It is a transparent background. But the grid is hidden to make it easier to design. For new users this can be deceiving since almost any other app is a white background unless you see the grid like in photoshop. In Illustrator, to fill you are required to have an object.