
App-wide Theme Switching with Tailwind v4 CSS Variable Overrides
When you think about implementing a theme system, the first instinct is to add conditional classes to every component. But what if you could swap the entire app’s color palette by changing a single CSS block — without touching any HTML? In Tailwind v4, that’s exactly what you can do. How Tailwind v4 Compiles Utility Classes Tailwind v4 compiles utility classes as CSS variable references: /* CSS generated by Tailwind v4 */ .bg-emerald-700 { background-color: var(--color-emerald-700); } .text-emerald-600 { color: var(--color-emerald-600); } .border-emerald-500 { border-color: var(--color-emerald-500); } bg-emerald-700 doesn’t hard-code #047857 — it references var(--color-emerald-700). Change that variable and every element using bg-emerald-700 updates instantly. ...
