Hello @vanillalily,
Thanks for reaching out. There's currently no direct way to change the default color of the offset path created using the Object > Path > Offset Path option. By default, the offset path inherits the stroke and fill color of the original object, which can cause it to blend with the original if the colors are the same.
However, you can manually change the color of the offset path immediately after it's created. Here's how:
Create the Offset Path: Go to Object > Path > Offset Path and set your desired offset value.
Select the Offset Path: With the offset path still selected, go to the Fill or Stroke options in the toolbar or Appearance panel.
Change the Color: Choose a new color for either the stroke or fill to differentiate it from the original object.
This method requires a manual step each time, but it allows you to distinguish easily between the original object and the offset path. Feel free to contact us if you have more questions or need assistance. We'd be happy to help.
Thanks,
Anubhav