Note: This post preserves and references the solution from Ivan Aloneguid’s original article. Full credit goes to the original author for this elegant solution.

Quick Solution

If you use IntelliJ IDEA with a dark theme but want a white Markdown preview, here’s the simplest fix:

  1. Go to File → Settings → Languages & Frameworks → Markdown
  2. In the “Custom CSS” field, add:
body {
  filter: invert(1);
  background: #fff;
  font-family: 'Segoe UI';
  font-size: 16px;
}

img {
  filter: invert(1);
}
  1. Click Apply and OK

Why This Works

The CSS uses filter: invert(1) to flip the dark preview to light. Images are also inverted to preserve their original appearance. You can customize the font family and size to your preference.

This gives you the best of both worlds: keep your dark IDE theme for coding while having a comfortable white background for reading Markdown documentation.

Original Source: IntelliJ IDEA - Simplest White Markdown Theme by Ivan Aloneguid