Preface

Books are wonderful, but there is only so much you can do as a writer using a single colour. To add another dimension for your book writing, you might want to use styled text but Minecraft provides no immediate way to do this, considering you cannot insert the section sign (§) yourself and ampersand substitution as-provided in some modded servers will not work for this context.

There's a way to do it, and to explore this option for an easy and convenient in-game way, one must embrace modded clients. For this specific example, Book Formatting will be used. Since my only experience is with this software, whatever software for Forge which may exist to serve the same purpose may not have the advice shown here apply universally.

Modding

Launchers

If you're using the vanilla launcher, you're absolutely wasting your time. While you can install Fabric into an existing build of Minecraft created through Mojang's instance manager yourself, if you're just getting into modded clients than definitely check out a third-party instance manager like ATLauncher — it'll save you a lot of trouble and headache, especially because such launchers expose the game's console output in a user-friendly manner so if you encounter trouble that isn't immediately obvious, you can find where error output is and correct as-needed.

But also, it'll make installing mods hella-easy. Since this mod is Fabric- and Quilt-compatible, if you change to Quilt for any reason you can stay warm with the knowledge that most, if not all of your experience in Fabric will carry into Quilt.

The mod

After installing the mod into your Fabric-modded Minecraft instance, you'll be presented with this additional menu when writing a book:


But, it also provides an important function for rapacious editors with an unhealthy appetite for speed; §.

Keyboard editing

Of course, as shown in the provided image there's a GUI on the left side. But you honestly do not need it if you've committed Minecraft's formatting codes to memory, because you can press left alt any time you want to insert a formatting code. There are three ways formatting can be handled:

• Pre-formatting
  Codes can be inserted as you are writing but not used until you are finished. While you may encounter space constraints, those can be resolved the moment you are finished by filling in missing characters which wouldn't fit with this method. When you are finished with the initial writing, you can back-track to the characters and press left Alt to insert your section signs which will remove the formatting characters and apply their intended formatting instead.
  
• Post-formatting
  You can press left Alt to initialise the formatting process, at which point one character after the cursor will disappear — this is intended behaviour, as you may find if any characters coincidentally are a part of recognised formatting codes. You may then insert the code of your choice, and see the effect apply which will restore the missing character as it is no longer assumed to be a formatting code since the section sign precedes the intended formatting code.
  
• In-situ formatting
  You may also declare the formatting code before you begin writing. This may help with potential formatting issues if you can already visualise the page you want to write, but you should save bolded font last as explained in the next section.

You may also want to apply font styling along with colour. In this case you'll want to apply colour first, then styling afterward.

Examples

Styles can be applied in any order, but colour must always come first. In the event you want to incorporate styling with colour mid-way, incorporating colour will reset the formatting for text thereafter. So:
§oOblique text with a §1blue§r §ohighlight.
won't work. And because the colour will reset styling, the reset after would be useless. However;
§oOblique text with a §1§oblue§r §ohighlight.
will display as-intended. Here's an example with some bold lettering:
§oOblique text §lwith§r §oa §1§oblue§r §ohighlight.
As well, a dual-tone example building on the above:
§5§oPurple oblique text §lwith §5§oa §1§oblue §5§ohighlight.
And, one more dual-tone example with oblique bang if you're into that look:
§5I'm so §dexcited§o!

Edited — I removed the resets in colour-only examples because… that's for getting rid of formatting. If all you are doing is colour, §r can be skipped! Also, colour resets formatting, so use of colour resets existing text styling.

Lastly, if you want to reset formatting (at risk of losing some content), you can select all of the text and cut, then paste. Only visible characters will be copied (usually), so pasting the text will render no formatting whatsoever. You may have to do this a couple of times until all formatting has disappeared, depending on how much of it you used, and you may still have to further edit the document to remove any remaining section signs which might remain — I am unsure how effective it is at removing section signs as-of-yet, but I am aware it will reset the formatting for most instances.

Issues

You may encounter some use issues while formatting your book pages. Here they be, as well potential resolutions:

• Non-familiarity of book editing
  The Book Formatting mod is more crude than it lets on; You can't highlight words or phrases and apply formatting — all the left-side buttons do is what the keyboard interface described above earlier. And you also must reset the formatting mid-writing yourself. Don't expect to carry your word processor workflow into this.
• Alt-tabbing in a book
  While great to use for switching between windows, you'll need to get into the habit of pressing backspace to cancel section insert when habitually switching between windows, such as to copy a character that may be perfect to fulfill a technical need in your book.
• Inability to reset format
  This is a problem that can happen before and after a line. If you wish to use the reset code at any instance and you see it not working, try adding a character so reset ends up in the middle, or deleting characters in the event a section sign simply refuses to fit — pipe is useful in the former. You can delete additional characters prior or after formatting thereon.
• Invisible characters
  Because of how formatting in Minecraft works, section signs and formatting codes count as additional characters. Unfortunately, there is no resolution for this beyond stumbling through your writ, and even if you wipe out the formatting with a complete cut and paste. this issue may still be exhibited. Be aware and prepare to figure out a solution.
• Bold character offset
  Unfortunately, Minecraft doesn't have the presence of mind to correctly position a cursor in bolded font and the Book Formatting mod does not fix this. So bolded text should be incorporated last to ensure this offset isn't a problem while editing.

If you can work past all of those problems, you can make books that will be remembered not only for their detail per-page, but also be able to easily separate content in pages with colours. So whether it's for a trade book or journal, for adding purpose-specific text blocks or whimsical fun, you can add yet another dimension to your book writing and create better literature than peers who don't.