Is it possible to create an adjustment layer that will only apply to the clip(s) under it in the storyline. i.e. not any clips further below?

In FCP, I'm trying to create a mock news report. I added a Generator > Background > Drift... a slightly animated shape-based background.

The "anchor" was filmed in front of a green screen.

I've added a small upper thirds News logo... type thing... and I have a running "Text Scroll" title running along the lower third.

To get rid of the green screen, I just used the FCP native: Effect > Keying > Keyer, effect, and it almost got it all without me even needing to tweak anything.

So... anyway... it looks great, except, the skin tones on the anchor are terrible, and the white balance was all off during filming. So, I'd like to drop in some color correction on just the clips in the primary storyline (i.e. the news anchor.) However... there are easily 20-30 clips, and I don't want to copy/paste all the color corrections... the keyer and any other effect I choose to add... to all 20-30 clips. Because, if I make a small change to one, then I have to go down the line and update that setting for each clip. I guess I could just get the edits where I want them, and then sum all 20-30 clips into one compound clip... and then do all my color correction to this new compound clip. But... I need to find a solution that does not involve compound clips, for... several reasons that are beyond the scope of this message.

So.. basically... this might be a simple Yes/No question.

Is it possible to create an Adjustment Layer in Motion 5, that I can drop in my keyer, color corrections, and any other effects... and be able to just stretch this adjustment layer over 20... or even... 200 clips, but have it only affect the "news anchor" clips... and not change the Generator > Background layer that is "underneath" or... "behind" the primary storyline clips of the anchor?

I thought that, if I just created a simple "Title" project in Motion... deleted the "Text" layer that shows up by default... but left the "Title Background" placeholder... then... I could just save (publish) this Nothing-Title... and it would appear in FCP. Then I could drop in the title over the primary storyline... and the clips in the Prim. Storyline would be applied into the "Title Background" placeholder... and whatever effects I applied to this custom title, would only apply to the clips in the placeholder. But... when I try this, it doesn't work. It just applies the Keyer to the news cantor clips AND the "Background"

Am I missing something, or is there just no way for me to do what I want to do without some kind of compound clip situation?

Thanks guys!

BTW... I bough the Ripple Training courses for Apple Motion... and they are FANTASTIC! Thanks for the advice!