Update index.md

components/data-apps/general-design-guide/index.md

@@ -112,7 +112,22 @@ Use the following code for primary buttons; secondary buttons can be simple `st.
 {: .image-popup}
 ![Screenshot - Save Data](/components/data-apps/general-design-guide/pic3.png)
 
-
+```
+def ChangeButtonColour(widget_label, font_color, background_color, border_color):
+    htmlstr = f"""
+        <script>
+            var elements = window.parent.document.querySelectorAll('button');
+            for (var i = 0; i < elements.length; ++i) {{ 
+                if (elements[i].innerText == '{widget_label}') {{ 
+                    elements[i].style.color ='{font_color}';
+                    elements[i].style.background = '{background_color}';
+                    elements[i].style.borderColor = '{border_color}';
+                }}
+            }}
+        </script>
+        """
+    components.html(f"{htmlstr}", height=0, width=0)
+```
 
 **Example**
 ```