fix(ot): use default color constant for hex2rgb fallback

Co-authored-by: Philip Molares <philip.molares@udo.edu>
Signed-off-by: Erik Michelson <github@erik.michelson.eu>

public/vendor/ot/hex2rgb.js

@@ -1,16 +1,18 @@
+const defaultColor = { red: 0, green: 0, blue: 0 }
+
 function hex2rgb (hex) {
-  if (!hex || typeof hex !== 'string') return { red: 0, green: 0, blue: 0 }
+  if (!hex || typeof hex !== 'string') return defaultColor
   if (hex[0] == '#') hex = hex.substr(1)
   if (hex.length == 3) {
     var temp = hex
     hex = ''
     var match = /^([a-f0-9])([a-f0-9])([a-f0-9])$/i.exec(temp)
-    if (!match) return { red: 0, green: 0, blue: 0 }
+    if (!match) return defaultColor
     temp = match.slice(1)
     for (var i = 0; i < 3; i++) hex += temp[i] + temp[i]
   }
   var result = /^([a-f0-9]{2})([a-f0-9]{2})([a-f0-9]{2})$/i.exec(hex)
-  if (!result) return { red: 0, green: 0, blue: 0 }
+  if (!result) return defaultColor
   var triplets = result.slice(1)
   return {
     red: parseInt(triplets[0], 16),