Assuming you want the implied function as well as the appearance shown....
Make your data field transparent.
Put layout text behind it with the desired color, style, etc. (Grey and italics shown in your example).
Give it this conditional format:
Not IsEmpty ( YourTable::Yourdatafield )
and then specify a font size of 500 to make the layout text disappear when there is data in the field.
Thanks, Phil! That works great...
Oh yes, and if the data field can't be transparent, you can actually put the layout text on top of the field to get the same results...
Thanks for the follow-up. I actually had created a separate box filled with white and placed it way to the back to arrive at the same result; good to know I don't need to do that!
Since this post, I've upgraded to FileMaker 12 Advanced. Is this still the recommended way to do this?
I think I read somewhere that this "greyed-out" help text has a more direct solution now. Is this now a built-in feature of FileMaker 13?