Maybe that's the color they wanted it to be? Shocking idea, I know.
Now, how one could be so clueless? Well, let me enlighten you. This ship comes from a rather well known game, called Wing Commander. There's a rather well established appearance the Ralari has, and it's definitely not silver in color. Talon, is much more oriented in classics than you, and especially in early WC games, so I was surprised to see it colored like that. If this was a design choice, he'd have to justify it. Unlike most games today, Wing Commander does have a fairly well developed plot.
Good to know it's just because it's WiP though. A silver Ralari looks just... off, for some reason. Not exactly bad, but very strange.
For the reference, this is how it looks in WC1 (the one below):
http://www.wcnews.com/ships/wc1ralari.shtml