TOPIC: Yamaha 90 2-stroke tach

I am in the process of installing an '04 Yamaha 90 2-stroke in my '59 Dorsett Catalina. When I went to install the Yamaha tach, I noticed that there are two square multi-wire connectors and four loose leads coming out of the back of it. The two square connectors have mates under the cowling of the motor, so those were easy to figure out, but I need some help on the four loose leads. There are also four loose leads coming out of the shift control, one each black, yellow, green, and red. The loose leads under the cowling are one each black, yellow, green, and blue. My guess is that these should be connected, color-to-color, but should the red coming off the tach go to blue on the motor?

Any help would be appreciated.

Cheers,
Bill