I know Merle's are a mark of not being 100% purebred but I was wondering if there were any other coat colors that suggested anything other than 100% Siberian?

Merle's are the big one, pretty much any color/pattern outside of that is acceptable. Woolie coats are also a fault.

http://shca.org/shcahp5a.htm

So the splash coats/piebald/pinto coats are okay? I really like the patterns but hey, I liked Merle too. Haha.

Splash Pi and Pinto are all acceptable We have a few very nice Pi's and a few splash coats in our lineage, fingers crossed we'll get to see them in future generations as well

Good, good. The puppy we're looking has a really cool splash coat and I just wanted to double check!
I googled some images and they're gorgeous! I just haven't seen that many around. :/

They aren't super common, and the quality ones are even less common. So you found another puppy, YAY! Can't wait to see/hear more

We did! He seems to fit us even more than the other one. We're going to go look at him tomorrow and hopefully he'll be coming home with us! If he does, we'll be posting lots of pictures.

Do you mind me messaging you and maybe getting some advice on him?

Of course, you can PM me here or I can send you my email as well whichever is easiest

I just PM'd you on here.

If I were ever to see a brindle siberian, I would probably assume it's a mix too. But besides merle and brindle, I can't think of a color that would look like it would have to be a mix.