I would use a different approach than using conditional formatting. I would use a calculation field If(display="T";"Company Name";"") and then insert this as a merge field on to the layout.
I would guess that the second text color is a color style applied to the data in the field rather than to the layout field object.
When I want to hide text on a layout via conditional formatting, I use it to make the font size very large. If you have a single row of text in the 10-12 point range, a font size of 120+ will make the text disappear.