I am a very novice Illustrator user. I have recently been getting the following pop-up every time I go to copy text from one worksheet to another. This didn't use to happen: "The color swatch "PANTONE Black C" has a conflict with the current document." Options: Merge Swatches; Add Swatches; Apply to All."
Does anyone know how to get rid of this popup?
You don't really "get rid" of that message. You decide what you want to do. It is not an error message, it's a workflow message asking you how you want to handle the issue... a decision must be made and Illustrator will not make it for you (thankfully).
The conflict means you have 2 swatches with identical names -- one in the document already and one associated with the art you are pasting. But although the names are the same, the color definitions are different.
Merge will make the pasted art use the color from the existing swatch in the document, not the art you are pasting. So, you are telling Illustrator to discard the pasted art colors and redefine those colors based on swatches of the same name in the document. This can result in colors changing for the pasted art.
Add Swatches means you want to keep the colors all the same, and you want to change the names of the swatches associated with the art you are pasting. So, after you paste, you'll have additional swatches - such as
Pantone Black C and
Pantone Black C 2. This is helpful if you want to ensure all the color of the art you are pasting remains unchanged. You can always reassign different colors after you've pasted.
Apply to All means just that. Which ever of the above options you choose the same decision will be used for all swatch conflicts in this instance. This is not a "global" decision. The next time there's a swatch conflict you will see the same dialog and be presented with the same choice.
Most users really don't want to disable this permanently. It's a good idea to keep an eye on what's happening with colors when you copy/paste.
If you are doing a lot of copy/pasting between documents, using different names for swatches, or ensuring the color definitions for the swatches are all the same will prevent the conflict dialog from being initiated. Note that Pantone Black C is not the same as Pantone Black U or Pantone+ Black C or Pantone+ Black U.