Your Figma icons are lying to you: currentColor, dark mode, and React SVG

You know the pattern: the app ships on a light theme, icons look fine, nobody thinks about tokens. Later someone flips the UI to dark — black background, same icons — and half the toolbar vanishes. Not because CSS “broke.” Because the SVG still has fill="#000000" (or a hard-coded grey), and you never wired color through a variable / currentColor in the first place.

Easy to run into on a real project: theming arrives later, the icon keeps a fixed paint value, the theme flips, and the icon disappears on the new background.

This is not a “use a better icon pack” problem. It is a contract problem: the SVG was authored as paint on a canvas, but your app needs a glyph that inherits color.

Here is a solid mental model for icon reviews — and for converting SVG → React in the browser.

The lie in the export

Most design tools give you something like:

<svg viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg">
  <path fill="#000000" d="M12 2L2 7l10 5 10-5-10-5z"/>
  <path fill="#000000" d="M2 17l10 5 10-5M2 12l10 5 10-5"/>
</svg>

#000 is not “default.” It is a hard theme choice. Same trap with #111, #1A1A1A, black, or “almost black” greys from auto-export. Search the file for those before you merge.

Three contracts for an icon

Pick one. Mixing them is how icon systems rot.

• Paint — fixed colors in the file. Use for illustrations and logos with real brand hues.
• Glyph — shape only; color from CSS / props. Use for UI chrome (nav, buttons, inputs).
• Bitmap handoff — PNG/WebP for email, decks, or a CMS that rejects SVG.

UI chrome should almost always be a glyph. That is what currentColor is for.

The React shape that actually works

import type { SVGProps } from "react";

export default function LayersIcon({
  className,
  ...props
}: SVGProps<SVGSVGElement>) {
  return (
    <svg
      viewBox="0 0 24 24"
      width={24}
      height={24}
      fill="none"
      aria-hidden="true"
      className={className}
      {...props}
    >
      <path
        d="M12 2L2 7l10 5 10-5-10-5zM2 17l10 5 10-5M2 12l10 5 10-5"
        stroke="currentColor"
        strokeWidth={1.5}
        strokeLinejoin="round"
      />
    </svg>
  );
}

Why this shape:

1. currentColor — fill/stroke follow color / Tailwind text classes. One source of truth with the theme.
2. {...props} on the root — callers own className, size, tests, and a11y overrides without editing the file.
3. viewBox kept — width/height become layout knobs, not geometry.
4. aria-hidden by default — decorative; the button (or link) gets the accessible name.

<button type="button" aria-label="Layers">
  <LayersIcon className="text-sky-300" />
</button>

If Figma left a <title> inside the SVG, remove it when the control already has a name — otherwise screen readers announce twice.

Stroke vs fill trap: some Figma exports use fill, some use stroke, some mix both. Put currentColor on the attribute that actually paints. Leaving fill="#000" on a “stroke icon” is a classic silent miss in review.

Dark mode is a color problem, not a file problem

Wrong fix: ship icon-dark.svg and icon-light.svg.

Right fix: one glyph, theme via CSS.

<nav className="text-slate-700 dark:text-slate-200">
  <LayersIcon className="h-5 w-5" />
</nav>

Multi-color product marks (logo with two brand hues) are paint, not glyphs. Do not force those through currentColor. Keep them as static SVG / <img>, or pass explicit props (accent, muted) if you truly need theming.

React Native: same idea, different host

React Native does not render HTML SVG. You want react-native-svg, and numbers, not strings:

import Svg, { Path } from "react-native-svg";

export default function LayersIcon(props) {
  return (
    <Svg viewBox="0 0 24 24" width={24} height={24} {...props}>
      <Path
        d="M12 2L2 7l10 5 10-5-10-5z"
        stroke="currentColor"
        strokeWidth={1.5}
      />
    </Svg>
  );
}

width="24" vs width={24} is a classic RN footgun. Hand ports often forget one prop and fail in weird, quiet ways. If you generate JSX, emit numbers.

Paste-JSX vs SVGR — pick by volume, not ideology

Neither is “more professional.”

• SVGR (or similar) in the bundler — dozens of .svg files land in the repo every week.
• Paste JSX — one-off icon, design handoff, shareable preview, or you also need React Native output without wiring a pipeline.
• <img> / static asset — huge illustration that never recolors. Do not componentize it.

Paste-JSX wins when you do not want to touch Vite / webpack / Next config for a single mark. You can do that in SVGEditor: paste SVG, get React / RN JSX in the browser. SVGR wins when icons are a pipeline.

Before you trust any converter output, check three things yourself:

1. kebab-case → JSX (stroke-width → strokeWidth)
2. {...props} on the root <svg> / <Svg>
3. gradient / clip ids unique per file (two icons with id="paint0" on one page will fight)

Do not expect a converter to invent currentColor for you or uniquify every Figma id across your whole set. That is still your review.

Bundle cost (the part people skip)

A React icon is JavaScript in your bundle.

• 40 toolbar icons as components → usually fine
• one 200KB illustration inlined as JSX → you paid a tax for nothing

Rule of thumb:

• Chrome → component + currentColor
• Marketing / email / CMS → PNG or static SVG when the destination cannot theme

next/image is the wrong hammer for interactive icons. It will not give you prop-driven stroke/fill the way an inline component does.

Next.js App Router

Icon components without hooks are valid Server Components — they are just JSX. Colocate named files under components/icons/ so unused icons tree-shake. Avoid a mega icons.tsx barrel that re-exports the world and drags everything into the graph.

A 60-second checklist before you merge an icon

1. Grep for #000 / #fff / black / white that should be themeable → currentColor (or props)
2. currentColor is on the paint that actually renders (fill and/or stroke)
3. viewBox present
4. Root spreads {...props}
5. Decorative → aria-hidden; meaningful → name the control
6. Gradient / clip ids unique per file
7. RN path uses numeric props
8. Full illustration → static asset, not a component

If you have a sharper rule for icon reviews, drop it in the comments.👇