Overview

Describe a project in natural language and ColorUI generates a coordinated palette with an explanation for each color. Its OKLCH-based approach maps the prompt’s mood, temperature, and context to color properties, then groups results into primary brand tones, secondary accents, and neutral backgrounds. That gives a brief a more usable starting point than a lone suggested color.

ColorUI evaluates prompts statelessly through its backend API: prompts are not stored or tied to personal accounts. Palettes can be used in personal and commercial projects without attribution. ColorUI also presents the generator as part of a toolkit with more than 40 free tools and no sign-ups.

For a broader comparison, see our AI Color Palette Generators list.

Key features

Color names and exact hex codes can be specified and locked while the generator finds matching tones. This is useful when a project already has a brand color that must remain fixed; it also gives users more control than prompt-only generation. Seven harmony modes and a random mode broaden the ways to explore palettes.

Exports include CSS variables, Tailwind, SCSS, JSON, W3C DTCG, Style Dictionary, Swift UIColor, and Android XML. That breadth makes the results practical across web, design-token, iOS, and Android workflows. Integrations for Figma, VS Code, CLI, GitHub, Raycast, and MCP provide additional routes into existing work, though the range alone does not establish how deeply each integration is connected.

The public API needs no key or signup, supports CORS, and allows 60 requests per minute. Its palette endpoint accepts prompts, harmony rules, or random generation, with random counts from 2 to 8. That is a low-friction option for prototypes and modest integrations, but the request cap matters for higher-volume use.

The CLI has no dependencies, runs anywhere Node 18+ runs, has no telemetry, and supports self-hosted deployments through COLORUI_API. ColorUI says it uses strict CSP, HSTS preload, COOP, frame-ancestors none, SSRF guards, per-IP rate limits, and weekly CodeQL scans. Support is available by email and through a Discord community.

Pricing

Free — 0.00 USD per free, billed Free forever. There is no sign-up, no LLM, and no API key requirement; personal and commercial use is allowed without attribution. That is a strong fit for individual designers, developers, and projects that can work within the public API’s 60-requests-per-minute limit. The trade-off is that there is no paid plan described for teams needing a higher API quota or other expanded service.

Platforms

ColorUI is available on Android, iOS, web, and as an extension, API, or self-hosted option. The CLI’s Node 18+ requirement is relevant for developers deploying or using that route; self-hosting can be configured through COLORUI_API.

Who it's for

Choose ColorUI if you want to turn a written brief into a palette, preserve specific brand colors, and export directly into common design and code formats without creating an account. Its API, CLI, integrations, and self-hosted option also make it suited to developers incorporating palette generation into their workflow. It is less compelling if your priority is an established color catalogue or a product whose central offering is broader project and design management.

Pros and cons

Pros: Prompt explanations and OKLCH-based generation make the color choices easier to interpret than a bare set of swatches.
Pros: Locked names or hex codes help preserve existing brand colors while exploring complementary tones.
Pros: Broad exports, a no-key public API, and self-hosted CLI support accommodate both design handoff and developer workflows.
Pros: Stateless prompt evaluation and commercial use without attribution suit privacy-conscious and client-facing work.
Cons: The public API’s 60 requests per minute may constrain high-volume applications.
Cons: The free generator offers no LLM or API key; teams seeking a larger managed API allowance have no paid tier described.

Alternatives

Pantone Connect Palette Generator is worth considering if you want access to a catalogue of more than 15,000 colors and Search, Pick, and Measure tools; its free plan requires an account.
KColor is another free option for web and extension users.
AIColors is a free, web-based option with unlimited palette generation and no account required.
Chromos may suit readers who want a project-based palette workflow: its free plan allows one project and five palettes and includes color tools, explanations, advanced reasoning, and ADA optimization.
Coolors is an alternative for web, iOS, and extension users; its Pro plan is 3.00 USD per month.
HanoDecor Color Palette Generator is oriented toward design generation, with a Starter plan at 19.00 USD per month billed yearly ($228/year), alongside a displayed $38 price.
Perception offers a free Lite plan with up to three AI-generated palettes at a time, plus color-reference pages, favorites, and bookmarks.
Color Palette Generator AI is a free web and API alternative offering unlimited generations, every export format, shareable links, and no account requirement.

Verdict

ColorUI is a strong choice for designers and developers who want prompt-led palette exploration with brand-color controls, many export formats, and a genuinely low-friction API and CLI. Its combination of privacy-conscious prompt handling and commercial-use rights strengthens the case for client work. Look elsewhere if you need a higher-volume API allowance or would rather work from a large established color catalogue.