While google translate gives "marron" as the translation for brown in French, I have never heard it used, either in France, Canada or Belgium. Brown in French is brun.
You should also accept "lila" for purple in German.
I am french, and I'd say "marron" is the name we give to the colour whereas "brun" is only used in order to describe hair and eye colour. But I'm not even sure about that.
About lila, that is, and I should know it for i'm Austrian, a much lighter version of violett. An example for lila would be Milka and for violett MS OneNote would be an example. Lila is more blue, whereas violett is more pinkish. I'll allow lila anyway.
Don't makea generality out of your personal experience. The most common word for "brown" varies from place to place, but for the majority of native speakers, notably in France, "marron" is the generic term for brown and "brun" is reserved for hair and fur.
You should also accept "lila" for purple in German.