diff --git a/.changeset/bui-themer-bui-palette-additions.md b/.changeset/bui-themer-bui-palette-additions.md
new file mode 100644
index 0000000000..efd6d4a139
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+++ b/.changeset/bui-themer-bui-palette-additions.md
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+---
+'@backstage/plugin-bui-themer': minor
+---
+
+Introduce the Backstage UI Themer plugin. It adds a new page at `/bui-themer`
+that converts an existing MUI v5 theme into Backstage UI (BUI) CSS variables,
+with live preview and copy/download.
diff --git a/.changeset/unified-theme-attr-stack.md b/.changeset/unified-theme-attr-stack.md
new file mode 100644
index 0000000000..003e05018f
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+++ b/.changeset/unified-theme-attr-stack.md
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+---
+'@backstage/theme': patch
+---
+
+The `UnifiedThemeProvider` now coordinates theme attributes on the document `body` in case multiple theme providers are rendered.