All is in Blunderland

PPLLLFFFFFTBBRRATTTAATTAATTHONK!

K.I.T.T., who had been droning on and on about some riddle, gasps, "Dear Me, what in the world could you possibly have eaten to have so polluted the atmosphere that I'm crying, and I don't actually possess tear ducts. Get out."

"Wait," you say, "What about-"

"Get OUT!!!!!!"

You fall out of the car, coughing and laughing at your own putrid stench, and K.I.T.T. slams the door shut behind you. Standing up, you dust yourself off and find yourself staring at two doors in front of you. One is yellow, and the other is purple. Which door do you enter?