Seven additional colour variants for the VAULT counters and cabinets that are in the game files but not used.
You also need the VAULT lightfix from here for the cabinets with glass parts to display properly (they have wrong references by default, which are fixed in that fix). The no-drop VAULT cabinets (same post) are updated to include the hidden colours as well.
The counter islands do not have these additional variants, I checked (I guess that’s why they weren’t made available). All of the additional colour options are in the same catalogue thumbnails as the original items.
The counters have an alternate “no splash” version, which only uses the backsplash-less models (see the last screenshot). Use either one or the other, not both! No-Backsplash overrides for all of the Maxis basegame counters (including the original Vault colour variants) are here.