Fluid build up on engine
So I went to pick up some engine coolant today, bought the green kind instead of the pink, I read somewhere that it's fine in a pinch. I probably shouldn't have got the wrong kind but the VW stuff was more money than I had. And I put some in, and once I got home, I noticed steam drifting out of my engine. When I opened up the hood, there was a bunch of fluid built up on the engine. It's like rusty water.
I also noticed some weird yellow build up around the oil cap, and it is covered in it.
Did the wrong coolant do this? Or is this a more serious issue? To me it looks a hose is leaking but I'm not really a car guy so any info would be greatly appreciated.
It's a 2001 Jetta 2.0l, gas engine. The coolant I bought is Prestone 50/50, anti-freeze / coolant.