diff --git a/pkg/api/server.go b/pkg/api/server.go
index cf5f4041a..b162312d3 100644
--- a/pkg/api/server.go
+++ b/pkg/api/server.go
@@ -206,13 +206,15 @@ func Start(uiBox embed.FS, loginUIBox embed.FS) {
 		}
 
 		if ext == ".html" || ext == "" {
+			themeColor := c.GetThemeColor()
 			data, err := uiBox.ReadFile(uiRootDir + "/index.html")
 			if err != nil {
 				panic(err)
 			}
 
 			prefix := getProxyPrefix(r.Header)
-			baseURLIndex := strings.ReplaceAll(string(data), "/%BASE_URL%", prefix)
+			baseURLIndex := strings.ReplaceAll(string(data), "%COLOR%", themeColor)
+			baseURLIndex = strings.ReplaceAll(baseURLIndex, "/%BASE_URL%", prefix)
 			baseURLIndex = strings.Replace(baseURLIndex, "base href=\"/\"", fmt.Sprintf("base href=\"%s\"", prefix+"/"), 1)
 			_, _ = w.Write([]byte(baseURLIndex))
 		} else {
diff --git a/pkg/manager/config/config.go b/pkg/manager/config/config.go
index 07780db8c..9af0070a0 100644
--- a/pkg/manager/config/config.go
+++ b/pkg/manager/config/config.go
@@ -151,6 +151,9 @@ const (
 	HandyKey        = "handy_key"
 	FunscriptOffset = "funscript_offset"
 
+	ThemeColor        = "theme_color"
+	DefaultThemeColor = "#202b33"
+
 	// Security
 	dangerousAllowPublicWithoutAuth                   = "dangerous_allow_public_without_auth"
 	dangerousAllowPublicWithoutAuthDefault            = "false"
@@ -619,6 +622,10 @@ func (i *Instance) GetPort() int {
 	return ret
 }
 
+func (i *Instance) GetThemeColor() string {
+	return i.getString(ThemeColor)
+}
+
 func (i *Instance) GetExternalHost() string {
 	return i.getString(ExternalHost)
 }
@@ -1175,6 +1182,8 @@ func (i *Instance) setDefaultValues(write bool) error {
 	i.main.SetDefault(PreviewAudio, previewAudioDefault)
 	i.main.SetDefault(SoundOnPreview, false)
 
+	i.main.SetDefault(ThemeColor, DefaultThemeColor)
+
 	i.main.SetDefault(WriteImageThumbnails, writeImageThumbnailsDefault)
 
 	i.main.SetDefault(Database, defaultDatabaseFilePath)
diff --git a/ui/v2.5/index.html b/ui/v2.5/index.html
index f103a9650..5a1a71ce2 100755
--- a/ui/v2.5/index.html
+++ b/ui/v2.5/index.html
@@ -9,7 +9,7 @@
       name="viewport"
       content="width=device-width, initial-scale=1, maximum-scale=1"
     />
-    <meta name="theme-color" content="#202b33" />
+    <meta name="theme-color" content="%COLOR%" />
     <!--
       manifest.json provides metadata used when your web app is installed on a
       user's mobile device or desktop. See https://developers.google.com/web/fundamentals/web-app-manifest/
diff --git a/ui/v2.5/src/components/Changelog/versions/v0140.md b/ui/v2.5/src/components/Changelog/versions/v0140.md
index e6e0d81ac..8585d85b9 100644
--- a/ui/v2.5/src/components/Changelog/versions/v0140.md
+++ b/ui/v2.5/src/components/Changelog/versions/v0140.md
@@ -1,2 +1,3 @@
 ### 🎨 Improvements
+* Allow customisation of UI theme color using `theme_color` property in `config.yml` ([#2365](https://github.com/stashapp/stash/pull/2365))
 * Improved autotag performance. ([#2368](https://github.com/stashapp/stash/pull/2368))
diff --git a/ui/v2.5/src/docs/en/Configuration.md b/ui/v2.5/src/docs/en/Configuration.md
index 4bcef2a07..2d993cf9c 100644
--- a/ui/v2.5/src/docs/en/Configuration.md
+++ b/ui/v2.5/src/docs/en/Configuration.md
@@ -120,6 +120,7 @@ These options are typically not exposed in the UI and must be changed manually i
 | `custom_served_folders` | A map of URLs to file system folders. See below. |
 | `custom_ui_location` | The file system folder where the UI files will be served from, instead of using the embedded UI. Empty to disable. Stash must be restarted to take effect. |
 | `max_upload_size` | Maximum file upload size for import files. Defaults to 1GB. |
+| `theme_color` | Sets the `theme-color` property in the UI. |
 
 ### Custom served folders