Using commands to give a beacon any effects other than it's default effects have no noticeable result, when it's otherwise expected to give the alternate effect. It's my understanding this used to work (though I hadn't done so personally in the past).

Works fine on beacons: /blockdata ~ ~ ~ {Primary:10}
Doesn't work on beacons: /blockdata ~ ~ ~ {Primary:23}
Also true with similar commands like /setblock.