updating 17' pro to power trim/tilt

[Maverick49]

Iv'e got a 1990 tracker 17' pro that has all of the wiring in place for power trim but did not come with it from the factory, I have purchased the correct trim unit which has only two wires. The wiring harness on the boat has red,green,blue,tan & black wires that end in a female ended, black rubber boot/plug with five post type terminals, does this go to some type of relay switch and then to the trim unit? also the boat does not have a trim gauge. Any help would greatly apreciated.
Rick.