A lot of people tend to mistake horses who have duo-colored hair as tricolored horses, or bay/black paints with sunbleached red hairs as tri-colored horses. In truth though, there are very few if any horses with more than two base colors. Bay paints are not tri-colors because if they were, any solid bay with white could also could be considered tri. this
guy confused me a bit, and I'm still researching whether he's a true tri or not. more... click- wikipedia explanation
I believe that bridle would also be an offset of a true tri-color? I'm not sure though. here
is a nic thread on tri-colored paints once you scroll past all of the fake tri colored horses (the bays
) there is a little bit about dilutes and the difference about Bend 'or spots and some pictures of some real tri-colored horses also.
Either way, tricoloring is extremely rare and a very crazy thing. Interesting though, if you're into genetics!
Looked up that funky pony also, out of curiosity. If you'd like, theres a whole bunch on him here