DO YOU MEAN BY "真是白"?
IF YES, I THINK IT WOULD POSSIBLY BE "真是白癡!"
白癡 = DUNDERHEAD, BIRDBRAIN, IDIOCY, MOONCALF, CHUMP....ETC.
"癡" IS CROSSED OUT TO MAKE THE SENTENCE LESS OFFENSIVE.
AND THAT IS TO SAY "WHAT A(N)......!"
IF NOT, PLEASE PROVIDE US WITH YOUR FULL CONTEXT.