Features
Darkkle is a dark theme for the Google Sheets web app. Everything below runs locally in your browser.
Appearance
Backgrounds and text
Choose pure black or soft black for the sheet background, and white or soft white for text. Pure black suits OLED displays and very dim rooms. Soft black reduces the contrast step between the sheet and the surrounding interface.
Greys have three strengths — subtle, normal, and strong — controlling how far neutral interface greys move.
Coordinated theme tints
Picking a theme tint links four things at once: the selection colour, the row and column header highlight, the faint cell lines, and a coordinated drawn-border colour. Twelve tints are available, and every individual part can still be overridden afterwards.
The two quick styles, Simple Dark and Tinted, are starting points rather than locked modes. Any detailed control you change overrides them.
Cell lines and borders
Cell lines can be faint, grey, or bright, using either the theme colour or a custom colour. Borders you drew yourself can be rendered white, matched to the theme, or set to a custom colour.
Your colours are preserved
This is the design rule that matters most. Darkkle transforms neutral interface colours and leaves non-neutral colours you chose yourself as they are. A cell you filled amber stays amber. Conditional formatting keeps its meaning.
The trade-off is honest: a highly desaturated custom colour can be hard to distinguish from an interface grey, because it genuinely is close to one.
Canvas-aware header highlighting
When you select cells, the spreadsheet highlights the matching row numbers and column letters. Doing that correctly on a dark background is the hardest part of theming a canvas grid.
Version 2.3.0 carries a substantial repair covering:
- selected row numbers and column letters staying readable rather than being painted over;
- one consistent highlight colour across both headers;
- no compressed or stranded highlight left at a viewport edge after scrolling;
- no stale geometry reapplied to a retained canvas layer;
- correct behaviour across single cells, ranges, whole rows and columns, shift-extended selections, and multi-range selections.
This area remains sensitive to spreadsheet interface changes. See Known issues.
Per-spreadsheet profiles
Settings are saved per spreadsheet, not globally. A dense financial model can use strong greys and bright lines while a simple list uses a softer look, and each reopens the way you left it.
Profiles are mirrored to local and browser-sync storage where the browser supports it, with a page-local recovery copy.
Settings backup and restore
Export a portable JSON backup of all settings and import it elsewhere. This is the dependable way to move profiles between Chrome and Edge, because those browsers use separate sync services that do not talk to each other.
Backups contain settings and spreadsheet identifiers. Review a backup before sharing it.
Pinned settings panel
Selecting the toolbar icon opens the settings panel pinned beside the spreadsheet rather than as a popup that closes when you click away. You can adjust settings and watch the sheet change without the panel disappearing.
Most changes preview immediately. After a change, click once in the grid; that focus handoff completes any retained-canvas update.
Keyboard shortcut
Alt+Shift+N toggles the theme, when the combination is not already claimed by the operating system or another extension.
What Darkkle does not do
Deliberate omissions:
- No developer-operated server, account, or login.
- No analytics, telemetry, advertising, or usage tracking.
- No remotely loaded code.
- No access to browsing history, downloads, clipboard, cookies, or other websites.
- No modification of your formulas, values, comments, or stored formatting — it changes rendering only.
The full declaration is in Permissions and the privacy summary.