Border color and fill color grayed out in the form field properties

[Katherine27577054po1o]

When trying to modify the appearance of a form field, border color and fill color are grayed out. I go to Field properties accessed by double clicking the field, then go to the second tab "appearance" and I cannot change those two properties. I can get the default color by checking "Highling existing field under the fields menu while I'm in Prepare Form mode. The form is not locked. I am running Adobe Acrobat build: 18.9.2044.251705 on a MacBookPro OS Sonoma 14.5. Adobe cloud says I'm up to date with the software. It seems in the past there was some issue with this but some people said it was fixed. I can stumble along with a work around but would very much like access to the border color and line color (and adjust the line thickness). Any suggestions appreciated. Thank you!

[Bernd Alheit]

Is the form field locked?

[Katherine27577054po1o]

No the form field is not locked and permissions are read write.

[Tariq Dar]

@Katherine27577054po1o Was the form initially created by You or someone else? Also, was it made using Adobe Acrobat? Are those field PDF Form fields or Acrobat Sign fields? 
Please share the file with us if possible, and we will share our observations. With the limited information available, I assume those fields may be Acrobat Sign form fields.

~Tariq

[JR Boulay]

Be sure that the form field (not the form file) is not locked: