Come Out, Ye Black and Tans

A phrase daring the Black and Tans, pro-British constables during the Irish War of Independence, used by the Irish rebels.
It is famously known for being an idiom in an Irish rebellion song, "Come Out, Ye Black and Tans"p

Come out, ye black and tans, come out and fight me like a man! Show your wife how you won medals down in Flanders! Tell her how the IRA made you run like 'ell away, from the green 'n lovely lanes of Killeshandra!

OK

1. Agreeing on something; 2. Asking for another person to do something

Dude 1: Cheer me up, OK?
Dude 2: OK, I'll try.