I'm trying to crimp on the wires from the stock speaker wire harness to the new speakers, but there's 4 wires in the original harness. Do I just crimp the ones of the same color to each other and then crimp those to the new speaker wire?

 

I assume you are talking about the front speakers and it must have components. you can just hook them up together and just run them in parallel.

 

2 of the wires go up to the factory tweeter location. You can either re use those wires to feed your new tweeters (if you have components), you can just hook all 4 up, or you can find just the 2 that go to the body harness.