How can you update the specular color dynamically?

I've got an object in my game where I want to update the specular color on the fly, using ShaderGen. So I do the following in script...

myMaterial.specularColor[0] = "1.0 0.0 0.0 1.0";
reinitMaterials();

When I do this.... nothing happens. I have to flat out quit the game, change the specular color, save the material file, then reload. That doesn't seem right, since everything else I can change dynamically... so what's different about that?

-Dave Calabrese
Gaslight Studios