The answer to your question is of course not.
But this particular law you object to is trivial compared to the REAL problems we have in our public school system from leftwing indoctrination. Students reading Rigoberto Menchu instead of Adam Smith? Students being taught that the founding principles of our country are nothing but constructs used to prop up the power of racist, misogynistic, capitalistic oppressors, etc. etc.
You are elevating this triviality far beyond its real importance. Your arguments are those that should really be addressed in the Colorado legislature, and there are not enough facts in this article to justify your position. Was there a problem with marxist high school teachers permanently displaying certain flags (Vietnam, Nicaragua, Cuba, Venezuela, whatever the regime of the moment for the left is) having nothing to do with their teaching curriculum, but rather part of their leftwing indoctrination? Who knows? I don't, and I suspect that you are taking a strong position without knowing either.
I see what you're saying, but let's not throw out the baby with the bathwater. It's a geography class. The entire curriculm in a geography class has to do with nations of the world. Seeing flags is an excellent way to get kids interested and asking questions; much more so than just having them read from a textbook.
Yes, there is a problem with leftwing teachers. But that doesn't mean that kids should be deprived of receiving the most complete education as possible. Let's look at the situation. I don't know which other flags were displayed, but right now let's take Mexico and China. Well, Mexico is a huge issue right now and a neighboring nation. China is a huge trading partner and the most populous nation in the world. Kids should learn as much as possible about countries like these because chances are they will in one way or another become even bigger issues in our nation's future.
As far as the Colorado legislature is concerned I really don't care. When it comes to the government beareaucrats and education I could care less what the lawmakers say. Let's not forget that the lawmakers there still allowed a true POS like Ward Churchill to teach, and get paid, at a State university after his blatant anti-American behavior. So, you can see why I really don't care what any government says about what can and cannot be taught to children.