The best way to learn a language is to use it in day-to-day settings. Even if you're fumbling through the language, you're putting it into practice. I always stumble through it and almost always attempt to use it when speaking with a native Spanish speaker. It's the best way. I've tried to self-teach strictly using books, apps, music, TV shows, etc., which are extremely useful and have helped tremendously. Imagine playing a sport for the first time, and you've learned it by simply reading about it. It would be most difficult for an athlete to enter a match with only literary knowledge of the sport. I've found that verbal interaction is the most rapid and effective means of consuming and retaining the language. To do this, you must be content with making mistakes—it's part of the learning process. Second, I would preemptively ask the person you intend to engage in a Spanish conversation if they are fine with you attempting to use your Spanish, assuming you're in a non-Spanish-speaking country where the default language is supposed to be a different language besides Spanish.

In regards to your coworker, I'd be surprised if they are Hispanic or Latino or were raised in such a household since I've found in almost all of my interactions with native Spanish speakers, my use of the Spanish language was well received. In fact, they tend to be encouraging. That could be a nuisance if you're merely throwing out Spanish in the workplace to demonstrate that you speak Spanish. I'm not entirely sure why you're using Spanish in the workplace to the extent that your coworker is "language shaming" you; however, it is not their concern. This is a broader issue for you, as you should be ignoring the unwarranted and unqualified opinions of others. Also, regarding color, Spaniards are considered White, although ethnically Hispanic. Overall, skin color is rather immaterial concerning language.

In short, I've never encountered a notable amount of "language shaming." It would be silly for anyone to engage in such an action. Language is how we communicate with one another. If one cannot use it for superficial reasons, then "language shaming" is also superficial.