It depends on the context. If you're observing, for example, that many web servers use Apache, it would be entirely appropriate to say, "Apache has become the de facto web server of choice." If you're observing that many teenagers in your town die their hair blue, you probably wouldn't say, "Blue has become the de facto hair color", unless you deliberately wanted to create an odd-sounding phrase. You'd be more likely to say, "The latest fad is to die your hair blue."
Phrases with similar meaning that come to mind -- with varying levels of formality -- are "de facto standard", "accepted practice", "common practice", "trend", "fad", "craze", "pattern", ... probably many more.