I have seen that HTML signature in thunderbird will be shown as grey color. Even though my signature is not in grey color the default grey color will be shown. How to resolve this issue?

3 Answers 3


You can edit the signature in HTML by ticking the "use HTML" checkbox in the Signature Text box.

Then in the signature box type something like

<p style="color:red;" >Richard Holloway</p>


<p style="color:#000000;" >RICHARD</p>
  • It keep showing as in color gray if I have a dash before the name like: -Richard. Is there any way to prevent it? It seems black inside the Thunderbird but when I open the sent message in gmail (from browser) it is all gray.
    – alper
    Jun 11, 2020 at 21:06

The other answer didn't work for me. Thunderbird displays the signature in grey regardless, even when the email is sent out (at first i thought it was just at the editing stage).

1) find your profile folder in ~/.mozilla-thunderbird (it is a hidden folder)

2) create a folder called "chrome" inside of it

3) inside the "chrome" folder create an empty file called "userContent.css"

4) edit "userContent.css" in a text editor and add these lines:

 * 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;

5) restart thunderbird


Starting from Thunderbird 24, in Ubuntu/Mint Linux you have to do:

  1. mkdir ~/.thunderbird/chrome
  2. emacs ~/.thunderbird/chrome/userContent.css
  3. Add this to the file and save.moz-txt-sig, .moz-signature { opacity: inherit !important; }

  4. Add this code block to your HTML signature:

    <style><!-- .moz-txt-sig, .moz-signature { opacity: inherit !important; } --></style>

  5. Restart Thunderbird.

This technique will also prevent other Thunderbird users or e-mail clients from greying out (opacitating) your signature.

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