change text color of calculated field when viewed in browser

Hi, 

This custom validation for changing the text color of a calculated field works when the PDF is viewed in Acrobat.

But this doesn't seem to work when viewing the PDF in Chrome. Is there another option to get it to work in Chrome (or any browser)?

event.target.textColor = (event.value > 25 || event.value < -25) ? color.red : color.black;