Opera One: Blue Hour

Blue Hour is a custom theme package for Opera One. It bundles 11 video wallpapers, a full browser and keyboard sound pack, three color themes, and a 260-entry color system (130 dark, 130 light) into a single installable Opera theme.

This is not a Chrome extension. Blue Hour ships a manifest.json, but it only works through Opera's theme loading workflow. It will not install or run in Chrome, and it is not distributed through the Chrome Web Store.

---

What's inside

Component	Details
Wallpapers	11 video wallpapers (.mp4) with static previews
Wallpaper coverage	Fills the full browser surface, not just the new-tab page
Browser sounds	"Blue Hour" pack — tab, panel, split-screen, and island interaction sounds
Keyboard sounds	"Blue Hour Typing" pack — letters, space, enter, backspace
Color themes	Blue Hour Neon, White Frost, Black Onyx
Color-sets	130 dark entries, 130 light entries
Localization	English (_locales/en/messages.json)

Full-browser wallpaper

Unlike a standard new-tab background, the wallpaper in Blue Hour extends across the whole browser surface — it's part of the shell, not just something you see on a new tab.

Sound packs

Blue Hour includes two sound packs:

• Browser sounds — UI feedback for tabs, panels, split-screen, and islands.
• Typing sounds — a full keyboard set covering letters, space, enter, and backspace.

Both packs use audio taken from Mizumi, an existing Opera theme by Opera Software. I liked how those sounds felt and reused them here — I didn't create them.

Sound attribution: All browser and keyboard sound assets in this package originate from Mizumi, an Opera Software theme. Full credit for the audio goes to Opera Software. See Third-party assets below.

Color themes

Blue Hour ships three color themes, each with its own visual identity:

Theme	Style
Blue Hour Neon	The signature look — deep blues with neon accents
White Frost	A bright, cool-toned light variant
Black Onyx	A high-contrast, near-black dark variant

All three draw from the same underlying 130-entry dark and 130-entry light color-sets.

---

Repository structure

OperaOne-BlueHourTheme/
├── manifest.json               # Opera theme manifest (v3, schema_version 2)
├── iconimage.png                # 218px theme icon
├── background.js
├── wallpaper/
│   ├── preview.png
│   ├── *.mp4                    # video wallpapers
│   ├── previews/                # preview images
│   └── color_picker/
│       ├── accent.png
│       ├── dark.png
│       └── light.png
├── sounds/                      # .mp3 UI sound effects (15 files)
└── _locales/
    └── en/
        └── messages.json

Every path referenced in manifest.json must exist as-is — don't rename or remove assets, or the theme will fail to load.

---

Installation

1. Download or clone this repository.
2. In Opera One, go to opera://extensions.
3. Enable Developer mode (top-right toggle).
4. Click Load unpacked and select the OperaOne-BlueHourTheme folder.
5. Open Themes and select Blue Hour.
6. Pick your wallpaper, sound pack, and color-set from the theme's options.

Updating

1. Pull the latest changes (git pull) or replace the folder contents with the new release.
2. Go to opera://extensions and click Reload on the theme's card (or restart Opera).
3. Your selected wallpaper, sounds, and colors carry over, as long as the underlying asset filenames haven't changed.

Validation

The color system has been checked for structural correctness:

• Dark mode color-set: exactly 130 entries
• Light mode color-set: exactly 130 entries
• Verified against mod.vibe.color-sets — valid JSON, 0 invalid HSL values
• All HSL values fall within h: 0–360, s: 0–100, l: 0–100
• Every wallpaper, preview, sound, icon, and locale path referenced in manifest.json exists in the package

Contributing

Contributions are welcome — bug reports, new wallpapers, additional color-sets, or general fixes.

If you're submitting a PR:

• Keep any new color-set entries within valid HSL ranges (h: 0–360, s: 0–100, l: 0–100).
• Don't rename or move existing assets referenced by manifest.json unless you're also updating the manifest.
• Test that the theme still loads via opera://extensions before submitting.

Third-party assets

The browser and keyboard sounds bundled with Blue Hour are sourced from Mizumi, an Opera theme created by Opera Software. These assets are included here because I liked how they sounded — they are not original work, and no ownership over them is claimed. All credit belongs to Opera Software.