Yeah, too many colors. Tone them down. (Too many isn't generally THAT frowned upon, but it's very common to use as little as possible to hone your skills.)
Also, try antialiasing the windows at first. I think the one closest to us is the one that seems most out of proportion. Also, it doesn't look very 'ship'-y. Give it a texture, some more depth to it (There is some, as is.), a few hidden engines or a trail that signalifies where said engines are..