an ordinary chessplayer wrote on 06/26/24 at 23:44:14:

You are correct. I bought the Powerbook. Only now do I see that there is a Powerbase.

FreeRepublic - That's puzzling. The webpage for the Colle Powerbase shows what looks like a screenshot of a tabular view of a games database. Recognizable names such as Kramnik, Giri, and MVL appear in this table. Perhaps it's not readily accessible to the user, or it's not obvious how to change from the variation tree view that you're seeing to that database view.  Maybe I'll pick up one of these Powerbase products in the next ChessBase sale and check it out.

FreeRepublic wrote on 06/23/24 at 12:35:20:

FreeRepublic - I've thought about buying these Powerbase products in the past. If the games aren't in a CBV file, can you tell what file format is used instead?

Thanks all for the information, opinions, and resources provided. I enjoyed playing through the Lombardy-Keene game.

The only book I have on the Colle is Gary Lane's The Ultimate Colle, 2001. I still look at from time to time.

For something much newer, there is the Modernized Colle-Zukertort Attack by Milos Pavlovic, 2019. It is available at Forward-Chess. I suggest you look at the sample material:
https://forwardchess.com/product/the-modernized-colle--zukertort-attack?section=...

I haven't had much experience with ChessBase products, but in addition to the Simon Williams' work, already mentioned, there is Colle-Zukertort Powerbase 2019. It's less expensive than most books.
https://shop.chessbase.com/en/products/the_colle_system_powerbase_2019

The Gambit app works very well my small tablet. Available as an App-book or ebook at a reasonable price:
http://gambitbooks.com/books/A_Killer_Chess_Opening_Repertoire_-_new_enlarged_ed...

To my way of thinking White's ambitions are more focused on the middle game than on the opening.

I have only played the Black pieces. I fiancheto the queen's bishop and take pleasure if I can establish a stonewall first. While a complex game remains, White players sometimes appear deflated to see ...Ne4 before they have played Ne5.

Still, Black might do better playing very classically with ...c5, ...Nc6, and ...Bd6 as in a reversed semi-slav.

Most of my opponents have played c3. That is what I would choose as White. It seems very much like a system move. However, as Black, it is b3 that bothers me. It has a sound positional basis in bringing the queen bishop into play. It also threatens central play with c4. Both players can advance their c pawns. With this much central tension it's unclear if White will get the king-side play that he might have desired.

That particular sort of 4. e3 QID position still reminds me of a game Lombardy-Keene, which appears here with Keene's old notes.
https://www.chessgames.com/perl/chessgame?gid=1071420

Thx, Pawnpusher!

I went with Summerscale's "Killer Opening". AOC's advice was very detailed and the review he linked to made it clear that if you're serious about the Colle and want video, then the video being reviewed was just the beginning. In all, 5 different videos at about 30 euros each (3 by Miller on the Colle, the Torre, and the London and 2 on 1.d4 and c4. by Pert). But "Killer Opening" offers the opportunity to just get my feet wet and see if it is interesting while still emphasizing the Colle-Zukertort. However, the are 2 editions of that book and some reviewers felt the 2nd one, at 50 pages longer, left them feeling a little lost; they felt the 1st gave a better overview. Ordered the 2nd edition. Then, E-bay to the rescue, got a 1st ed. as well for 7 bucks. We'll see.

Thank you both for your helpful replies.