Looks like oil. :D As long as you don't see shavings, it's good.
That's encouraging too. The concern was that if there's a head gasket leaking, some fluid could get into the crankcase. Running it then could be catastrophic.
You can't miss the discoloration when coolant gets into it. It gets foamy greyish.
FWIW - I am experienced, but not what I'd necessarily call a mechanic. And not being able to get in and crawl around the truck's engine compartment is really limiting. Hopefully your neighbor will make the right connection right away.
knowledge is power and the fact that you have went out of your way to contribute and share that knowlege with the community is awesome. I feel this post is a perfect example of how the community interacts with each other to solve a problem. Thank you for all the information you have shared today.