Make a custom 2 second black solid.

HI,

I'm trying to make a 2 second and a 1 second Custom Background Solid to saved use over and over again instead of having to put a 10 second one on a timeline and changing the duration every time.

Here's what I have been doing:

1) Right clicking a Custom Black Solid in FCP X and choosing "Open in Motion."

2) Motion opens.

3) I change the in and out points and push the video to the left so it's only 2 seconds.

4) I "save as" then I publish it to FCP X and name it

5) When I go back to FCP X, I see it but when I put it on the timeline it's still 10 seconds long.

What am I doing wrong?

Thanks in advance.

Imac 27" Retina 5K

16 GB RAM

Motion