Greetings qej,
There seem to be a variety of shapes and colors of the Klingon Trefoil. FASA gaming manuals used one that had a tall upper piece in red, the right piece in green, the left piece in blue - with a yellow circle in the middle. I have also seen the blue and green colors switched. There is a more modern version (Imperial?) that is a dark red on a black circle, and a dark red one on a silver circle (cover of "Star Trek Klingon for the Galactic Traveler"). Doing a search at Memory Beta
http://memory-beta.wikia.com/wiki/Trefoil (these are not considered canon) you'll see these images, or do a Google Images search. Keep in mind that the shape is often varies.
You will have to decide between the "Imperial Trefoil" and the "Classic Trefoil" - the latter being much more colorful.
We do expect you to post a picture of your new tat when you get it.
Klag