matching colors:

 

 

 

saving filters:

 

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Open the transition into the viewer. Make it the way you want it, and go to Make Favorite Effect.
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if you apply a combination of effects to a clip and you'd like to save and reuse that combination of effects/settings again then you can save them together as a filter pack
create a new bin in your Effects >> Favourites folder, that bin will be your "pack" (or you could create a new project to hold all your custom effects, if so, then create the bin in that project)
now load the effected clip into your Viewer window and switch to the Filters tab
in turn, or together, drag the filters from the clip into the new bin
note that the filter combination probably acheives the desired look only when applied in a specific order ... FCP however lists them in alphabetic order, so its advisable to rename each effect with a numeric prefix

so that's it. you've created a filter pack. when you want to apply that particular combo then you just drag the folder itself to the clip and all the contained effects will be applied