CSS Theme Generator

Turn brand colors into CSS variables

A practical web theme needs more than one primary color. Buttons need hover states, cards need surfaces, focus rings need transparency, and borders need a tint that works with the page background. This CSS theme generator starts with a compact set of brand choices and derives a small custom-property block you can paste into a stylesheet. The result is intentionally simple: useful variables for a landing page, prototype, documentation site or small app without the overhead of a full token pipeline.

Choose primary and accent colors, then set the background and text color that define the overall contrast. The browser derives hover, surface, muted text, border and focus values by adjusting HSL lightness and applying transparent RGB where appropriate. The preview card uses the same variables shown in the output, so you can quickly see whether the set feels coherent before copying it.

Using the generated :root block

CSS custom properties are easiest to maintain when they describe purpose instead of raw hue. A name like --color-primary tells future contributors where the value should be used, while --color-blue may become inaccurate after a redesign. Paste the generated :root block near the start of your stylesheet, then reference the variables in components. For example, buttons can use --color-primary, hover states can use --color-primary-hover, and panels can use --color-surface with --color-border.

Refining a starter theme

Derived colors are a strong first pass, not a substitute for testing. Review the theme with real headings, body copy, disabled controls, form fields, links and alerts. If the hover color feels too dark, raise its lightness manually. If borders disappear on the background, increase their contrast. Most importantly, run contrast checks for text on buttons and surfaces. The generator keeps all work in the browser, so it is safe for early brand exploration, but a polished design system still needs human review and component-level adjustments.