It also has references so you can go back and find HTML
color tables, lists of HTML tags,
A tutorial site that offers either of those has already failed.
What are "HTML colours" ? Now "grey/gray" is perhaps justifiable, but
you don't need a table to tell you how to spell "red" or "black".
Useful colour work needs to be done with the numeric form, not the
names. And please tell me they're not still pushing a "web-safe"
palette.
A "list of HTML tags" is doubly bad. They're elements, not tags. It's a
trivial distinction to learn and any half-competent tutorial should be
teaching it. Students who emerge from a course talking about "tags" have
failed to understand how SGML is structured, to a level that's necessary
for competent web designers.
Secondly HTML is defined by a DTD, not a list. If you don't teach the
relevant nesting rules, then you encourage students to mis-use elements
and produce horrors like <a><div>...</div></a>
This stuff is not hard to learn, but it's very badly taught almost
everywhere. In particular it's a broad topic and usually the wrong
things are being taught. You don't need to teach "valign" or "vlink" to
new students, or anyone other than an already skilled developer who now
wishes to learn archaeology.
W3Schools is an inaccurate site in many ways. These are inexcusable for
anyone claiming to be a serious tutorial. If you can't do, then don't
teach.