The King, reluctant to lose his favorite daughter, led her suitor to a chamber with three passageways leading from it.
"The Princess's room is along one of these", the King explained, "but warlocks and vampires infest the other two.
But the guards will, of course, guide you to the Princess.
As you know, the guards represent each of the three tribes in our land and are easily discernible by their clothes:

• The guard wearing black is a compulsive liar;
• the one in white is very honest;
• and the guard in grey invariably alternates truth with falsehood."

So saying, the King left. But the wily fellow had brought the suitor at night, when all three guards were wearing red nightshirts.

• "I never wear white," said one. "The Princess is down the corridor on the right."
  
• "I don't wear grey," said another, "and the centre passageway leads to the Princess."
  
• "I don't wear black", said the third, "and you should take the left-hand passage to find the Princess."
  

Which passageway should he take?

My solution.

"I never wear white,"
 - White wouldn't say this cos it would be a lie
 - Black  wouldn't say this cos it wouldn't be a lie
 - so this must be Grey

"I don't wear grey"
 - Black  wouldn't say this cos it wouldn't be a lie
 - so this must be White and the Princess is in the centre