ColorUI Prompt Palette Studio

colorui.io

Free plan Open source WebmacOSiOSAndroidAPISelf-hosted

Spec score 8.7 #1 of 22 in AI Color Palette Generators

What it is

ColorUI Prompt Palette Studio turns natural-language design requests into color palettes and explains each color's role. It maps mood, temperature and context to OKLCH properties, arranging colors as primary brand tones, secondary accents and neutral backgrounds. You can give it color names or exact hex codes, lock those choices and generate matching tones around them. Exports include CSS custom properties, W3C design tokens and Tailwind themes, alongside SCSS, JSON, Style Dictionary, Swift UIColor and Android XML. The public API needs no signup or API key, supports CORS and allows 60 requests per minute; it accepts prompt-based generation, harmony rules or random mode, with random counts from 2 to 8. Prompts are evaluated statelessly and are not stored or tied to personal accounts. Palettes may be used personally or commercially without attribution. Integrations include Figma, VS Code, CLI, GitHub, Raycast and MCP. ColorUI also lists image color extraction, an accessibility checker and seven harmony modes. The free plan is available without signup.

Spec sheet

What it does: Prompt Palette Studio turns a natural-language design brief into an OKLCH palette and explains each color's role.Read 15 Oct 2026 · colorui.io
Audience: ColorUI describes itself as a toolkit for designers and developers, with more than 40 free tools and no sign-ups.Read 30 Sep 2026 · colorui.io
Integrations: ColorUI provides integrations for Figma, VS Code, CLI, GitHub, Raycast, and MCP.Read 30 Sep 2026 · colorui.io
Support: Support is provided through [email protected] and a Discord community link.Read 30 Sep 2026 · colorui.io
Accessibility commitment: The accessibility statement names WCAG 2.2 AA, EN 301 549, Section 508, and the European Accessibility Act as standards it follows.Read 15 Oct 2026 · colorui.io
AI limitation: The maker warns that prompt generation does not itself perform precise WCAG contrast verification or color-vision-deficiency simulation.Read 15 Oct 2026 · colorui.io
API access: The public API requires no API key or signup, supports CORS, and allows 60 requests per minute.Read 30 Sep 2026 · colorui.io
API authentication: Normal API use requires no account or API key.Read 15 Oct 2026 · colorui.io
API limits: The palette endpoint accepts prompt-based generation, harmony rules, or random mode, with random counts from 2 to 8.Read 30 Sep 2026 · colorui.io
Browser extension: The browser extension supports Chromium browsers including Chrome 116+, Edge, Brave, Arc, Opera, and Vivaldi.Read 15 Oct 2026 · colorui.io
Browser extension status: The maker says the Chrome Web Store submission is still under review and provides sideload instructions.Read 15 Oct 2026 · colorui.io
Built-in intents: Preset intents include luxury, fintech, startup, wellness, gaming, education, nature, travel, minimal, sports, vintage, and wedding themes.Read 15 Oct 2026 · colorui.io
CLI: The CLI provides palette generation, WCAG contrast checks, and color conversion through npx or global npm installation.Read 15 Oct 2026 · colorui.io
CLI deployment: The CLI has zero dependencies, runs wherever Node 18+ runs, has no telemetry, and supports self-hosted deployments through COLORUI_API.Read 30 Sep 2026 · colorui.io
CLI requirements: The CLI is a single approximately 9 KB JavaScript file with zero dependencies and requires Node 18 or newer.Read 15 Oct 2026 · colorui.io
CLI self-hosting: CLI users can set COLORUI_API to route requests to their own deployment.Read 15 Oct 2026 · colorui.io
Color control: Users can specify color names or exact hex codes and lock those colors while matching tones are generated.Read 30 Sep 2026 · colorui.io
Color locking: Users can specify color names or exact hex values and have the generator preserve them while matching other tones.Read 15 Oct 2026 · colorui.io
Color model: The generator maps mood, temperature, and context to OKLCH color properties.Read 30 Sep 2026 · colorui.io
Commercial rights: Generated color palettes may be used in personal and commercial projects without attribution.Read 30 Sep 2026 · colorui.io
Commercial use: The maker states generated palettes may be used commercially without attribution.Read 15 Oct 2026 · colorui.io
Exports: Palettes can be exported as CSS custom properties, W3C design tokens, or Tailwind themes.Read 15 Oct 2026 · colorui.io
Figma integration: The Figma plugin generates palettes, applies colors to selections, checks WCAG contrast, and converts color formats.Read 15 Oct 2026 · colorui.io
Founder: The About page identifies Harsh Mistry as ColorUI's founder.Read 15 Oct 2026 · colorui.io
Independent criticism: Gridinsoft flagged limited independent reputation data, low estimated traffic, and the site's recent registration as caution signals.Read 15 Oct 2026 · gridinsoft.com
Independent domain age: Gridinsoft reported the domain as approximately two months old at its May 26, 2026 check.Read 15 Oct 2026 · gridinsoft.com
Independent hosting detail: Gridinsoft identified Cloudflare as the hosting provider and recorded IP address 104.21.58.247.Read 15 Oct 2026 · gridinsoft.com
Independent registration detail: Gridinsoft reported creation on April 28, 2026 through HOSTINGER operations, UAB, with Lithuania listed for the registrant.Read 15 Oct 2026 · gridinsoft.com
Independent security result: Gridinsoft reported zero provider warnings and no major malware or phishing detections in its scan.Read 15 Oct 2026 · gridinsoft.com
Independent technology finding: Gridinsoft classified colorui.io as an installable web application with Cloudflare Browser Insights and Google Tag Manager detected.Read 15 Oct 2026 · gridinsoft.com
Independent trust rating: Gridinsoft gave colorui.io a trust score of 52 out of 100 on its May 26, 2026 automated review.Read 15 Oct 2026 · gridinsoft.com
Intent mapping: Its algorithm maps prompt mood, temperature, and context to OKLCH color properties.Read 15 Oct 2026 · colorui.io
Local processing claim: The product page says generation runs locally without an LLM, account, or API key.Read 15 Oct 2026 · colorui.io
MCP integration: The MCP server supports Claude, Cursor, Zed, Windsurf, and Continue through a one-line npx configuration.Read 15 Oct 2026 · colorui.io
MCP tools: MCP exposes palette generation, harmony palettes, WCAG contrast checks, and CSS color conversion.Read 15 Oct 2026 · colorui.io
Open-source licence: ColorUI states that its web client, API, extensions, plugins, CLI, action, MCP server, and Raycast client are MIT licensed.Read 15 Oct 2026 · colorui.io
Palette structure: Generated results contain primary brand tones, secondary accents, and neutral backgrounds.Read 15 Oct 2026 · colorui.io
Prompt generation: It translates natural-language design prompts into cohesive color palettes with per-color explanations.Read 30 Sep 2026 · colorui.io
Prompt privacy: Prompts are evaluated statelessly through the backend API and are not stored or associated with personal accounts.Read 30 Sep 2026 · colorui.io
Public API: The REST API exposes convert, contrast, and palette endpoints, is CORS-open, and allows 60 anonymous requests per minute.Read 15 Oct 2026 · colorui.io
Raycast integration: The macOS Raycast extension offers palette generation, contrast checking, conversion, and clipboard-to-share-URL commands.Read 15 Oct 2026 · colorui.io
Release news: The changelog records an April 1, 2026 public API release with OpenAPI 3.1 documentation, importable collections, and SDK-generation support.Read 15 Oct 2026 · colorui.io
Security controls: The security page lists strict CSP, HSTS preload, COOP, frame-ancestors restrictions, SVG sanitization, SSRF guards, per-IP limits, and weekly CodeQL scans.Read 15 Oct 2026 · colorui.io
Security response: ColorUI promises vulnerability acknowledgement within two business days and high or critical fixes or mitigations within 14 days.Read 15 Oct 2026 · colorui.io
Self-hosting: Every listed client supports overriding the API base so an organization can run its own deployment.Read 15 Oct 2026 · colorui.io
Toolkit scope: ColorUI describes the wider product as more than 40 free color tools with no sign-up.Read 15 Oct 2026 · colorui.io
VS Code integration: The VS Code extension adds inline color swatches, local hover contrast grades, prompt palettes, and cursor conversion.Read 15 Oct 2026 · colorui.io

Plans and prices

Free Free Free forever no sign-up · no LLM · no API keys · commercial use without attribution Read 15 Oct 2026 · colorui.io

Every ColorUI Prompt Palette Studio plan and price →

Strong points and limits

Strong points

Explains colors in generated palettes
Locks named colors or exact hex codes
Exports CSS, W3C tokens and Tailwind themes
Personal and commercial use without attribution

Limits

API allows 60 requests per minute
Random mode generates 2 to 8 colors

Who it suits

It suits designers and developers who want to generate, refine and export palettes for design systems or code. Its API and integrations also suit workflows that need palette generation across tools.

ColorUI Prompt Palette Studio in depth

Read the full write-up

Overview

ColorUI Prompt Palette Studio is a prompt-driven palette generator for designers and developers who want to take color direction from a brief into working formats. It is most compelling when you need a no-sign-up workflow and control over colors that must stay fixed; the API’s 60-requests-per-minute cap is a practical constraint for heavier automation.

It turns natural-language descriptions into coordinated palettes and explains the colors it chooses. ColorUI says prompts are evaluated statelessly through its backend API, without being stored or associated with personal accounts. Generated palettes can be used in personal and commercial projects without attribution.

ColorUI positions the generator within a toolkit of more than 40 free tools, also offered without sign-ups. For a broader comparison, see AI Color Palette Generators.

Key features

The generator maps a prompt’s mood, temperature, and context to OKLCH color properties, then builds a palette with primary brand tones, secondary accents, and neutral backgrounds. That structure is useful when a project needs a coordinated starting point rather than a single suggested color. Users can name colors or supply exact hex codes and lock them while matching tones are generated, a meaningful control when an existing brand color cannot change.

Seven harmony modes provide another way to shape results; random mode accepts counts from two to eight. Exports include CSS variables, Tailwind, SCSS, JSON, W3C DTCG, Style Dictionary, Swift UIColor, and Android XML. AI-generated palettes can also be exported as CSS custom properties, W3C design tokens, or a Tailwind theme. The breadth suits both design handoff and implementation, though the palette generator remains one part of a larger toolkit rather than a full design system.

ColorUI also offers image color extraction and an accessibility checker. Integrations cover Figma, VS Code, CLI, GitHub, Raycast, and MCP. The public API needs no key or signup, supports CORS, and accepts prompt-based generation, harmony rules, or random mode. Its 60 requests per minute limit makes it useful for modest integrations, but a constraint for high-volume generation.

The CLI has no dependencies, runs wherever Node 18 or later 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 offered by email at [email protected] and through a Discord community.

Pricing

The Free plan costs nothing, billed Free forever. It requires no signup and has no LLM or API keys; personal and commercial use without attribution are included. That removes account setup and licensing friction, while the API’s 60-requests-per-minute ceiling is the stated throughput limit. There are no paid tiers in the plan information provided.

Platforms

ColorUI lists Android, iOS, web, API, extension, and self-hosted availability. Its integrations include Figma, VS Code, CLI, GitHub, Raycast, and MCP, and the CLI runs on Node 18 or later. The range supports both browser-based palette work and development workflows, with self-hosting available through the CLI’s COLORUI_API configuration.

Who it's for

This is a strong fit for designers and developers who want prompt-based palette ideas, need to preserve named or exact colors, and value exports that travel into code or design-token workflows. Its no-sign-up API and stateless prompt handling also suit users who want to avoid account-linked prompt storage. Look elsewhere if your integration needs more than 60 API requests per minute.

Pros and cons

Pros: Locked color names or hex codes let users keep an existing brand color while generating complementary tones.

Pros: A broad set of code and token exports covers common paths from palette creation to implementation.

Pros: Free forever, no signup, no API key, and commercial use without attribution lower the barriers to adoption.

Pros: Stateless prompt handling and a CLI with no telemetry offer clear privacy-oriented choices.

Cons: The public API is capped at 60 requests per minute, which may not suit high-throughput use.

Cons: ColorUI is a palette and color toolkit, not a complete design system.

Alternatives

Choose Pantone Connect Palette Generator if access to a 15,000-plus-color library and its Search, Pick, and Measure tools matters more than ColorUI’s prompt and code-export workflow; its free plan requires an account.

Chromos is worth considering for a web-based workflow whose free plan combines one project and five palettes with color tools, explanations, advanced reasoning, and ADA optimization.

Perception may suit readers who want a web-based reference workflow: its Lite plan offers three AI-generated palettes at a time, color-reference pages, and limits on saved palettes and bookmarks.

ColorBrew is another free option for web and extension users.

HanoDecor Color Palette Generator is an alternative for readers seeking a paid design workflow; its Starter plan is $19 a month, billed yearly at $228/year, and includes credits, designs, styles, HD exports, and projects.

10015.io AI Color Palette Generator is a free web tool for AI-generated palettes and CSS-variable or hexadecimal text export.

AIColors offers unlimited palette generation without an account, according to its free plan.

Color Palette Generator AI is a free web and API alternative with unlimited generations, all export formats, shareable links, and no account required.

Verdict

Choose ColorUI Prompt Palette Studio if you want prompt-led palettes with meaningful color locking, broad implementation exports, and a no-sign-up path from generation to API or CLI use. Its free forever terms and privacy-oriented prompt handling are persuasive strengths. For high-volume API workloads or a complete design system, its rate cap and focused palette scope point toward another tool.

Verdict

ColorUI combines prompt-led palette creation with color locking and formats for design and development workflows. Its stateless prompt handling and no-signup API are useful specifics, while API throughput is capped at 60 requests per minute.