I'm a little confused by your question myself. Stainless steel rust should be that same brown color. Though it can get very dark when dried. Blue is weird but purple isn't an uncommon description, assuming everything is still dark and there's lots of sediment.
But what's the question? Are you trying to fix it? Just determine what's rusting?
Oh yeah, the question is "can I use the knife and the glass again?"
Although, now that I look closely at them, the butter knife got eaten away in spots and it's already pretty cheap, so I'll toss it.
I'd answer "probably" if you've cleaned everything. But if the rust comes back then probably should just toss. Rust is an oxide layer, so outside only