So what's up with code being highlighted like it has errors when it doesn't, even in the tutorial vids? Confusing.

Workspaces (along with any other text editor you'll find, other than maybe Notepad) automatically changes what color certain parts of your code is written in to denote that it means something to the code. For example, notice the coloring here:

<!-- This is a comment. Notice how it's colored differently than the text inside the tag -->
<h1 class="purple" id="header">This is text inside of a tag, which is colored differently from the tag itself</h1>

In the case above, Treehouse colors the comment green to show that it's a comment, and won't actually render on the page. It colors the tags green, too, which is coincidental that it's colored the same as the comment. The text inside the tags is colored orange, because it's text that will display. The text ""purple"" and ""header"" is colored purple, because it's the value of an attribute, and means something different to the browser than everything else. Look at this next example:

html{
  background: green;
}

.purple{
  color: orange;
}

#header{
  font-family: monospace;
}

Notice how all the attributes and their values are colored orange. That's simply because they're all attributes and their values. The punctuation is colored white/light gray, because it's necessary punctuation, and the color points that out. The html part is colored green because it's a selector for a tag. Like wise, .purple is orange because it selects a class, and #header is yellow, because it selects an id. Basically, what I'm trying to say is that the text you write is supposed to be colored, and that color has different meanings, and those meanings are not necessarily errors

I understand the text color denoting different classifications and functions, I'm referring to the red highlight that is meant to denote an error, but often crops up when there is nothing incorrect or incomplete.

I'm with you Josh, I know exactly what you mean. I've seen most of these "errors" on media queries.

Here's a post by me 3 months ago on the same subject (https://teamtreehouse.com/community/media-wrong) - still no clue why they appear...

That's exactly what I was referring to. Just wanted to point it out if it was something Treehouse needed to correct. Thanks Michael.

I just started experiencing this. I thought it was a button i pressed lol