Palette Thief: Steal Colors from Any Image

We've all been there. You find a photo that has exactly the right vibe, and you want those colors in your project. So you squint at it. You try to eyeball the hex. You Google "color picker from image" and end up with some ancient Flash-era website that wants to install a toolbar.

That's what this week's builder fixed.

Palette Thief is a fully browser-based color extraction tool built entirely with the Canvas API, zero backend, zero server calls. Drop in any image and it pulls the 6 most dominant colors out of it, displays each one as a full swatch with HEX, HSL, and RGB values, and lets you copy any value with a single click. There's a toast confirmation so you know it worked. Clipboard stuff is finicky enough that you want that reassurance.

The export options are what make it genuinely useful. You can download the whole palette as a PNG card, which is the obvious one. But you can also export a .md file of the palette, which is the one developers will actually reach for. Drop it straight into your project docs or a design token reference. No reformatting, no copy-paste gymnastics.

It ships with both dark and light themes and a toggle to switch between them. The dark default is a near-black that doesn't compete with the colors you're looking at. The light theme is there for people who prefer it, or for when you're presenting and the projector washes everything out.

The whole app runs in the browser. No account, no auth, no upload limits, no server-side processing. Your image never leaves your machine.

Why frontend-only on a full-stack platform?

Not every problem needs a backend. The Canvas API handles color extraction entirely in the browser, so there was no reason to add a server. Keeping it client-side also meant a clean privacy story: your image never goes anywhere. This builder knew exactly what the problem called for and didn't add complexity it didn't need.

Why build something that already exists?

Because familiar problems are honest tests. Color pickers are everywhere, so you know exactly what good looks like and where things fall short. You're not evaluating the idea, you're evaluating the build. Three prompts to something you'd actually use is the point.

The prompts that built it:

Build an app called Palette Thief. Users drag and drop or upload any image. On upload, extract the 6 most dominant colors using the Canvas API and display them as large swatches in a clean dark UI. Each swatch shows HEX, HSL, and RGB values. Clicking a value copies it to clipboard with a toast confirmation. Add an "Export Palette" button that downloads the swatches as a PNG card. Style it with dark near-black background and clean modern typography.

Then two follow-up prompts: add .md export, and add a light theme with a toggle.

Three prompts. A browser tool that a real designer would actually use, shipped in an afternoon.

[Try it →] Built with Mayson