It's also not wise to try and hide any text using colored fonts. (cio.com)
Again, like meta tags, it seems to me that the prohibition on false, deceptive, misleading hidden text is enough. (lawyerist.com)
If you feel the need to hide the friendship from your partner, for example hiding text messages, then you are emotionally cheating and you'll need to ask yourself what is wrong in your relationship. (elitesingles.com)