About Random Colours
A random colour generator produces an arbitrary colour each time you generate, without any input from you. Random colours are useful when you need visual variety — placeholder images, data visualisation test data, UI mockups, game elements, generative art or just design inspiration when you don't know where to start.
This generator uses the browser's Math.random() function to pick a value for each RGB channel, giving over 16.7 million equally likely colours in Full mode. The other modes constrain the range to produce colours that feel a certain way — bright, pastel, dark, warm or cool — because truly uniform randomness often produces muddy, mid-tone colours that don't look interesting on their own.
Colour modes explained
| Mode | Range | Feel |
|---|---|---|
| Full | Every channel 0–255, uniform | Completely unpredictable — anything goes |
| Bright | At least one channel ≥ 200 | Vivid, saturated, high-visibility |
| Pastel | High lightness (65–90%), medium saturation | Soft, gentle, baby-shower palettes |
| Dark | Low lightness (10–35%) | Moody, deep, sophisticated backgrounds |
| Warm | Hue biased toward reds, oranges, yellows (0–60° or 330–360°) | Cosy, energetic, autumnal |
| Cool | Hue biased toward blues, greens, purples (180–280°) | Calm, technical, aquatic |
Keyboard shortcuts
| Key | Action |
|---|---|
| Space | Generate a new random colour |
| L | Lock or unlock the current colour |
| C | Copy the current HEX code |
| P | Switch between Single and Palette mode |
When to lock a colour
Random generation is best when it produces variety, but sometimes you find a colour you love and want to explore variations around it. Locking a colour keeps it fixed while you keep shuffling, so you can see how other random colours sit against it — useful for testing contrast, finding complementary accents or building a palette around an existing brand colour.
Common use cases
Design inspiration
Break out of a creative block with an unexpected colour.
Placeholder data
Generate unique colours for charts and dashboards.
Testing UI
Try components against unpredictable colours.
Game dev
Random colours for teams, avatars or particle systems.
Generative art
Feed into procedural drawing tools.
Teaching
Illustrate colour theory with immediate examples.
Privacy and accuracy
This random colour generator runs entirely in your browser. All generation happens locally in JavaScript with the browser's built-in random number generator. Nothing is transmitted, stored or logged on any server.