README: Fix colour for BIP 79

Author: luke-jr

README.mediawiki

@@ -392,7 +392,7 @@ Those proposing changes should consider that ultimately consent may rest with th
 | Nicolas Dorier
 | Standard
 | Draft
-|- style="background-color: #ffffcf"
+|- style="background-color: #ffcfcf"
 | [[bip-0079.mediawiki|79]]
 | Applications
 | Bustapay :: a practical coinjoin protocol