diff --git a/lib/identicon.rb b/lib/identicon.rb
index 2e40173..4ccc22a 100644
--- a/lib/identicon.rb
+++ b/lib/identicon.rb
@@ -8,22 +8,22 @@ class Identicon
   CHARS_REGEX = /(\w)(\w)/
 
   COLORS = {
-    a:   [196, 108, 168],
-    b:   [127, 219, 107],
-    c:   [83, 89, 215],
-    d:   [111, 198, 148],
-    e:   [186, 130, 82],
-    f:   [113, 66, 197],
-    "0": [201, 186, 84],
-    "1": [114, 153, 205],
-    "2": [141, 108, 204],
-    "3": [75, 183, 114],
-    "4": [192, 86, 82],
-    "5": [199, 115, 209],
-    "6": [206, 77, 94],
-    "7": [211, 135, 162],
-    "8": [71, 194, 197],
-    "9": [188, 110, 93]
+    :"a" =>   [196, 108, 168],
+    :"b" =>   [127, 219, 107],
+    :"c" =>   [83, 89, 215],
+    :"d" =>   [111, 198, 148],
+    :"e" =>   [186, 130, 82],
+    :"f" =>   [113, 66, 197],
+    :"0" =>   [201, 186, 84],
+    :"1" =>   [114, 153, 205],
+    :"2" =>   [141, 108, 204],
+    :"3" =>   [75, 183, 114],
+    :"4" =>   [192, 86, 82],
+    :"5" =>   [199, 115, 209],
+    :"6" =>   [206, 77, 94],
+    :"7" =>   [211, 135, 162],
+    :"8" =>   [71, 194, 197],
+    :"9" =>   [188, 110, 93],
   }
 
   class << self