When I use the text in the comment tool, I can't change the colour or font size. The property bar is grey.
Hi pauls5588579 ,
Could you please tell what application do you have- Reader/Acrobat?
What Operating System do you have-Windows/Mac?
Assuming you are facing an issue with Text Box in Comment tool in Acrobat, try to close Acrobat and restart the Computer, and then try to change the colour and font size . If that doesn't work,check if there is any update available for Acrobat.
Also, visit this link :Commenting in PDFs, Adobe Acrobat DC
Let us know about the results.