diff --git a/.github/workflows/preview-theme.yml b/.github/workflows/preview-theme.yml
new file mode 100644
index 0000000..c0203c3
--- /dev/null
+++ b/.github/workflows/preview-theme.yml
@@ -0,0 +1,29 @@
+name: Theme preview
+
+on:
+  pull_request:
+    types: [opened, synchronize, reopened]
+    branches:
+      - master
+      - theme-preview-script
+    paths:
+      - "themes/index.js"
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v1
+      - name: setup node
+        uses: actions/setup-node@v1
+        with:
+          node-version: "12.x"
+
+      - name: npm install, preview theme
+        run: |
+          npm install
+          npm run preview-theme
+        env:
+          CI: true
+          PERSONAL_TOKEN: ${{ secrets.PERSONAL_TOKEN }}
diff --git a/package.json b/package.json
index d167c1b..af82b59 100644
--- a/package.json
+++ b/package.json
@@ -6,18 +6,22 @@
   "scripts": {
     "test": "jest --coverage",
     "test:watch": "jest --watch",
-    "theme-readme-gen": "node scripts/generate-theme-doc"
+    "theme-readme-gen": "node scripts/generate-theme-doc",
+    "preview-theme": "node scripts/preview-theme"
   },
   "author": "Anurag Hazra",
   "license": "MIT",
   "devDependencies": {
+    "@actions/core": "^1.2.4",
+    "@actions/github": "^4.0.0",
     "@testing-library/dom": "^7.20.0",
     "@testing-library/jest-dom": "^5.11.0",
     "axios": "^0.19.2",
     "axios-mock-adapter": "^1.18.1",
     "css-to-object": "^1.1.0",
     "husky": "^4.2.5",
-    "jest": "^26.1.0"
+    "jest": "^26.1.0",
+    "parse-diff": "^0.7.0"
   },
   "dependencies": {
     "dotenv": "^8.2.0",
diff --git a/scripts/preview-theme.js b/scripts/preview-theme.js
new file mode 100644
index 0000000..6a0eaa6
--- /dev/null
+++ b/scripts/preview-theme.js
@@ -0,0 +1,76 @@
+const core = require("@actions/core");
+const github = require("@actions/github");
+const parse = require("parse-diff");
+require("dotenv").config();
+
+const parsePullRequestId = (githubRef) => {
+  const result = /refs\/pull\/(\d+)\/merge/g.exec(githubRef);
+  if (!result) {
+    console.log("Reference not found.");
+    return 297;
+  }
+  const [, pullRequestId] = result;
+  return pullRequestId;
+};
+
+async function run() {
+  try {
+    const octokit = github.getOctokit(process.env.PERSONAL_TOKEN);
+    const pullRequestId = parsePullRequestId(process.env.GITHUB_REF);
+
+    let res = await octokit.pulls.get({
+      owner: "anuraghazra",
+      repo: "github-readme-stats",
+      pull_number: pullRequestId,
+      mediaType: {
+        format: "diff",
+      },
+    });
+
+    let diff = parse(res.data);
+    let colorStrings = diff
+      .find((file) => file.to === "themes/index.js")
+      .chunks[0].changes.filter((c) => c.type === "add")
+      .map((c) => c.content.replace("+", ""))
+      .join("");
+
+    let matches = colorStrings.match(/(title_color:.*bg_color.*\")/);
+    let colors = matches && matches[0].split(",");
+
+    if (!colors) {
+      await octokit.issues.createComment({
+        owner: "anuraghazra",
+        repo: "github-readme-stats",
+        body: `
+        \rTheme preview (bot)
+        Cannot create theme preview
+        `,
+        issue_number: pullRequestId,
+      });
+      return;
+    }
+    colors = colors.map((color) =>
+      color.replace(/.*\:\s/, "").replace(/\"/g, "")
+    );
+
+    let titleColor = colors[0];
+    let iconColor = colors[1];
+    let textColor = colors[2];
+    let bgColor = colors[3];
+    const url = `https://github-readme-stats.vercel.app/api?username=anuraghazra&title_color=${titleColor}&icon_color=${iconColor}&text_color=${textColor}&bg_color=${bgColor}&show_icons=true`;
+
+    await octokit.issues.createComment({
+      owner: "anuraghazra",
+      repo: "github-readme-stats",
+      body: `
+      \rTheme preview (bot)  
+      \r![](${url})
+      `,
+      issue_number: pullRequestId,
+    });
+  } catch (error) {
+    core.setFailed(error.message);
+  }
+}
+
+run();