Visually impaired user having issue with comments in Acrobat

I am working with a visually impaired user who works in contrast mode on his PC. When he replies to sticky note comments in Acrobat, he can see them but they appear in white when he sends the PDF to me and other users., so we can't read them. Any ideas about why this is happening or if there's a fix? It seems as if you can only set the color on a brand new comment, but not on replies. I can select the white text in the comment and clear the formatting but obviously that's not an ideal solution. It doesn't make any sense to me because contrast mode shouldn't affect what's happening to the PDF itself, only what he's seeing on his screen. I am attaching a screen shot of what I'm seeing on my end.  Note comments form casmith.