Actually, now that I think about it, if it was the Tallest, shouldn't it be RED and purple text, not blue and purple..? Then again, the red would blend into the background worse than the purple Irken text... Also, that's the way Happy had the voices before, according to the archives. It may or may not be the Tallest... But the ' purple' one certainly talks like the Purple Tallest.
"Dropping a warship on me is cheating...take it back!"
"Having left his homeland, he never yields, never retreats, and never regrets. He faces forward and never looks back! He's manly! He's tenacious! Kamina of Team Gurren is here to take you on. Lets go!"