This is a bit messy and, I think, buggy. I recently ran into the problem that in some cases, you have to use the English term in localised apps (I checked English Intn'l, French, and German installations), and in other cases you need the localised term. For example, in the French ID you need to specify Black as "Black" (not "Noir", as the interface would suggest). On the other hand, the French version doesn't like "Dashed" as a line style, you need "Tirets". The German version has the same asymmetry.
One approach is always to use a try/catch statement, trying the localised version and if that fails, doing the English version, but that's not exactly what you want. The trouble is that to find this out systematically, you need to bother people with different installations to try and find out what works and what doesn't.
Apart from Dave's reference, you can also check "JavaScript Tools Guide CS3" (in ESTK, Help > SDK), from pp. 92 and 206.
Peter