How to Create a Custom Dark Theme in Opera

Custom Dark Mode for Opera: Extensions, CSS, and Settings

Dark mode reduces eye strain, saves battery on OLED screens, and creates a focused browsing experience. Opera doesn’t always offer a single built-in “custom dark mode” that fits every site or preference, but you can combine Opera’s settings, extensions, and custom CSS to get a consistent, personalized dark theme. This guide shows three practical approaches — quick settings, extensions, and using custom CSS — plus tips to fine-tune and troubleshoot.

1. Quick built-in settings

• Enable Opera’s dark theme: Go to Settings (Alt+P) → Appearance → Theme → select Dark. This changes Opera’s UI (tabs, toolbar, menus) but not page content.
• Use system dark mode: In Settings → Browser → Use system theme — Opera will follow your OS dark/light preference.
• Reader Mode: For articles, click the reader-mode icon in the address bar (if available) to get a simplified dark view.

2. Extensions to darken websites

Extensions are the easiest way to apply site-wide dark styles and often offer per-site controls.

• Recommended extensions:
  • Dark Reader — Highly configurable: brightness, contrast, sepia, font settings, and per-site toggles. Best for accuracy and readability.
  • Midnight Lizard — Detailed color schemes, schedule, and per-site profiles.
  • Turn Off the Lights — Primarily video-focused dimming plus a page darkening option.
• How to install:
  1. Visit the Opera Add-ons store (addons.opera.com) or Chrome Web Store (Opera supports many Chrome extensions — install “Install Chrome Extensions” first).
  2. Search the extension name and click Add to Opera (or Add to Chrome if using the Chrome store).
• Key settings to adjust:
  • Brightness / Contrast: Lower brightness and raise contrast for less glare.
  • Mode: Auto, dark, or dynamic (inverts colors intelligently).
  • Font smoothing: Adjust if text looks washed out.
  • Filter lists / site exceptions: Disable for sites that break (banking, CAPTCHA-heavy sites).

3. Custom CSS (for power users)

Applying your own CSS gives the most control but requires more setup. You can inject CSS using an extension like Stylus or by creating a local extension.

• Install Stylus:
  1. Add Stylus from the Opera or Chrome store.
  2. Click Stylus → Manage → Write new style → choose “URLs on the domain” or global (“”).
• Useful CSS snippets:
  • Basic global dark background and light text:

    css
    Copy CodeCopied
    @-moz-document regexp(”.“) {
    html, body {
        background: #111 !important;
        color: #ddd !important;
      }
      a { color: #66aaff !important; }
      img, video { filter: none !important; }
    }
    

  • Reduce glare on images (use sparingly):

    css
    Copy CodeCopied
    img, video {
      filter: brightness(0.9) contrast(0.95) !important;
    }
    

  • Force card backgrounds and inputs dark:

    css
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    input, textarea, select, .card, .panel {
      background: #1a1a1a !important;
      color: #e6e6e6 !important;
      border-color: #333 !important;
    }
    

• Tips for writing CSS:
  • Use specific selectors to avoid breaking layout.
  • Prefer rgba/hsla to fine-tune translucency.
  • Test on multiple sites; maintain a per-site override list.

4. Blending approaches and scheduling

• Combine Opera’s dark theme for UI + Dark Reader for pages + Stylus for site-specific tweaks.
• Some extensions support scheduling (sunset to sunrise). Use this to auto-switch modes.
• Use per-site exception lists to keep critical sites (banking, government) in default mode to avoid functionality issues.

5. Troubleshooting common issues

• Broken layouts or invisible elements: disable extension for that site or add CSS exceptions.
• Poor image/video colors: allow images to bypass filters or add exceptions in your extension.
• Login forms not visible or CAPTCHA fails: add site to extension whitelist.
• Performance: reduce extension filters or disable on heavy pages.

6. Accessibility and readability tips

• Prefer high contrast (text ≥ 4.5:1) for readability.
• Increase font smoothing and size if small text becomes hard to read.
• Use sepia or slightly warmed dark backgrounds to reduce blue light.

7. Quick checklist to set up a custom dark mode

1. Enable Opera Dark theme for UI.
2. Install Dark Reader, set global dark mode.
3. Add Stylus and create per-site CSS tweaks for any broken sites.
4. Configure schedules and per-site exceptions.
5. Test critical sites (banking, email) and whitelist if needed.

Custom dark mode in Opera is highly achievable with built-in themes, extensions like Dark Reader, and targeted CSS tweaks. Combine them for the best mix of aesthetics, readability, and functionality.