Great thread idea. As a layout editor, this kinda stuff always gets me going/thinking.
I'm thinkin'...something like the following (to be used as a guidelines throughout):
Three Colors, maintained throughout, one bright baseline shade for the banners, headers and one muted shade for any sidebar boxes, using within tables/charts, etc...:
Red for the "Classic" options: stuff that was basically just the Basic/B-X/BECMI game: the original 4 races, 4 base classes, 3 point alignment, etc...
Blue for the "Legacy" Options: stuff that was more AD&D through some elements of 3e: the additional 3 "traditional" races, the rest of the AD&D classes,maybe Psions too if they are going to have them, 9-point alignment, Fort/Will/Ref Defenses, etc.
Gold/Yellow for the "Whatever we're calling the third set of options that most closely resemble (or are directly pulled) from 3-4e or some completely new stuff.": Dragonborn, Tiefling, Eladrin, Warlords, Warlocks, Sorcerers, the "Priest" class they want to introduce, perhaps the 4e Shadowmagic-Assassin (the AD&D Assassin would be in the Blue/Legacy options), 5-point alignment, etc...
Then things that are really "new" to 5e or are to be used across the board are just in the book, sprinkled throughout (depending on how many levels the initial books follow, this might include such things as stronghold building, henchmen/hireling rules, morale, etc...that have been missing for many incarnations of the game and brought back in new and different ways).
Chapters are still broken up by topic, not color: so you have a 'Races" chapter, a "Classes" chapter, a Themes chapter, Abilities and ability score generation, an "Alignment" chapter (with the caveat that the use of Alignment in any fashion is entirely optional), a Defenses/Saving throws chapter, a "How to Run Combat" (
without minis!) chapter.
Things like Weapons/Damage type, Weapon type v. Armor type, Special combat "moves" (charging, tripping, grappling) go sidebars in the Combat chapter as optional add-ons.
Things like using a 6-attack type saving throws vs. the default Fort/Will/Ref defenses, go in a [reddish] sidebar as an alternate option for use...with guidelines, of course, of how to use them in a game
with the F/W/R at the same time.
Equipment and weapon/armor types are fairly standard, simple chapter with a few lists/tables with prices alongside.
Spell lists, descriptions, etc. are self-explanatory with [blue] sidebars or notations about/for using clerical "Domains" and "Schools" of arcane magic.
Optional Appendix: "Tactical Combat with Minis" go in an additional [gold] chapter or appendix, in the rear.
Optional Appendix: "Using Monsters as PCs" with guidelines for transitioning creatures from the MM into playable characters.
(depending on how high level the book goes) Optional Appendix: "Mass Combat/Warring across the world".
I can't really think of any/everything else at the moment, but I think you get the gist.
So you can have the DM/group say "We're playing a 'Red' game." or "a 'Blue' game" or "We're using Gold rules with Red & Gold characters." or "We're playing 'Rainbow' or 'the Color Wheel'" (i.e. everything in the book goes.)
And illo's! LOTS of illustrations, a couple of humorous cartoons, neat "corner" or "margin" graphics.
Howzzat?
--SD
