No, you are not understanding. I had the same reaction. You went in too pushy. You were hired as an assembly line worker, not as a designer or even a tech.
People who have worked together for a long period of time will always reject the new guy coming in and telling everyone what he knows. You have to prove yourself. You didn't take the time to do that.
As to the racial thing, I would say, could be. Although some will disagree, being white is not requirement for being a racist.
The other thing I noticed was he said you didn't fit in. Again, you were forcing your way into their established community and they resented the newcomer that wasn't like them and didn't speak their language.
We are not trying to pound on you. We are trying to help you. When you go in to a new situation, just lay back a bit. Instead of eagerly sharing your ideas, work hard at learning the current process. Sure, the language issue is a problem, but you could have sought out the better English speakers and asked for their guidance. Once you learn their system you will find ways to include your ideas and if you do improve the product or the process with one of your ideas, then you get the recognition.
Think about it from the converse perspective. If a total stranger who can't do what you have been doing for 10 years tries to tell you something that runs counter to your knowledge and experience, what is your first reaction.
Part of this is on them. They didn't do enough to get you oriented.
Sorry you had such a miserable experience - hope you learn from it.