Cursor color under emacs for read only files.

[Christian Klugesherz]

Dear emacs users

My configuration is following: Sun Solaris 8 and Emacs 20.3
My question concerns the cursor color under emacs.
To configure that, I use next code in .emacs file

(setq default-frame-alist
   '(
         (cursor-color     . "greenyellow")
         (cursor-type      . box)
     )
)

This works well when I open read/write files.
But when I open "read only" files, the cursor changes to another color
???
Could somebody help me, and tell me where I can configure the cursor
color for a "read only" file

Thanks in advance

Chris