Boundless gives you three independent layers to play with: the accent color that runs through the interface, the background style behind it, and an optional ambient effect drifting over the top. They combine freely, so you can end up with something quiet and plain or something rather more theatrical. All of it lives under the Settings tab.
Accent themes
There are ten accent themes:
- Boundless, the default
- Nova
- Ink
- Mono
- Reverse
- Blossom
- Ember
- Mint
- Royal
- Void
The accent runs through buttons, highlights, selection states, and the small pieces of color that tell you what is interactive. Changing it changes the whole feel of the app without touching anything about how content is laid out.
Matching app icons
Each of the ten accent themes has a matching alternate app icon, so the icon on your Home Screen can agree with the app you actually open. Pick the icon from the same area of Settings where you choose the accent.
Background styles
The background style sits behind the interface. There are six:
- Standard
- Brand Wash
- Aurora
- Midnight
- Sunset
- Void
Standard is the plain option. The other five are animated gradient washes that move slowly behind your content rather than sitting still.
Brand Wash is worth calling out: it follows whichever accent theme you have chosen, so changing your accent changes the wash along with it. The rest have their own character regardless of accent, and the honest advice is to try each one on your own device. Gradients read very differently on an OLED phone in a dark room than they do in a screenshot.
Ambient effects
On top of everything else, you can add a particle field:
- None
- Snow
- Rain
- Stars
- Sakura
- Fireflies
These drift across the interface as a slow, low-key layer. They are decoration, and they are entirely optional: None is a perfectly good answer, and it is the right one if you want the interface to hold still.
Ambient effects animate continuously while they are on screen, so if you are watching battery life on a long reading session, turning the effect off is the simplest saving available in the app.
Putting a combination together
A few starting points, none of them prescriptive:
- Quiet and neutral: Mono or Ink accent, Standard background, no ambient effect. Nothing competes with the page.
- Consistent color: any accent you like with Brand Wash, so the background always agrees with the accent, plus the matching app icon.
- Night reading: one of the darker washes with the effect set to None, so the interface stays calm in a dark room.
- Seasonal: Blossom with Sakura, or a cooler accent with Snow, if you enjoy the app changing with the year.
You can change any of the three layers at any time, and none of them affect your library, your progress, or how content is fetched.
What appearance settings do not touch
Appearance is presentation only. It does not change:
- which sources you have installed, covered in Adding sources
- your library, history, or reading positions, covered in Your library
- reader gestures and auto-scroll, covered in Reading
Your appearance choices are stored in device settings. Signed out they stay on that device, so setting up a new one means picking your combination again.
For what is available on which platform, see Getting started, and for release notes on new themes and effects, the blog is the place to look.