How do I look up laws regarding state car inspection?

I live in Texas, and took my car to get an inspection, which owners must do once a year here. The inspector turned my car down for a MINOR technicality regarding the color of my turn signal, and I believe the inspector was mistaken, because I took my car somewhere else and it passed. Now, I want to look up the actual laws regarding the state inspection requirements. How do I do this? For that matter, how do I look up laws on anything? This is one thing that has always bothered me. How am I supposed to know what the laws are if they are not in an easily accessible location, and written in English (not "legal-ese", which I don't speak)?