Signature display color

By default, Thunderbird displays the signature text which appears below the signature separator ("-- ") in the color gray. If you wish to change this to another color, insert the following into your "userContent.css" file. Note: this changes only the way that signatures are displayed in Thunderbird and will not affect the color of any signatures that you use with outgoing messages.

/*
 * Change display color of text and links in signature
 */
.moz-txt-sig, .moz-signature {
  color: black !important;
}
.moz-txt-sig > a, .moz-signature > a {
  color: blue !important;
} 

The above example will make the signature text black and links in signatures blue. You can use other colors as desired.