added purple

a.html

@@ -17,10 +17,13 @@
         #white{
             background-color: white;
         }
+        #purple{
+            background-color: purple;
+        }
         button {
             border-radius: 5px;
-            width: 100px;
-            margin: 5px;
+            width: 60px;
+            margin: 1px;
         }
     </style>
 </head>
@@ -31,6 +34,7 @@
     <button id="red"onclick=setColor('red')> red</button>
     <button id="blue"onclick=setColor('blue')>blue</button>
     <button id="white"onclick=setColor('white')>white</button>
+    <button id="purple"onclick=setColor('purple')>purple</button>
     <button onclick=randomColor()>random</button>
 </body>
 </html>