Update copilot button color

Author: combimauri

src/styles/base.css

@@ -26,6 +26,10 @@ body {
   padding: 0;
 }
 
+#chainlit-copilot-button {
+  background-color: #310ef1;
+}
+
 .MuiStack-root .css-2fbwda {
   display: none;
 }