Accidentally split the clip and audio

Hi people, 

I am new to both here and final cut. I experienced this several times where the clip got separated from the audio, but its different detaching the audio because in this case, the audio still syncs and attaches to the clip as if its ONE.

I included a photo. Do you know what shortcut I may have mis-clicked to cause that to happen? What is the benefit of this feature? 

Side question: can anyone tell me how to open the color picker in FCPX. I checked out Apple's color picker help page but I can't find the 'color well' to use control-click with.

  support.apple.com/en-gb/guide/final-cut-pro/ver0ed1dc9d5/mac

Thank you!
  

You have expanded the audio. You either double clicked the audio waveform or used Control-S. Either shortcut will also collapse the audio. You use expanded audio to overlap the audio of adjacent shots in split edits. Once you've overlapped the audio portions you can still collapse the expanded clips. 

You access the color picker in the Inspector when you have something selected that uses color selection.  I'll use a title as an example.  Select the text, in the inspector, go to the Face section.  If you click the color swatch, you get the traditional Apple color picker.  If you click the downward arrow to the right of that swatch, you get a pop-up color selection tool.  Color picker is only available with tools that use color adjustmens.