How did you create this signature? The grey colour is by design; Thunderbird automatically fades all signature text by adjusting its opacity. See the comments [http://kb.mozillazine.org/Signature_display_color here] about Thunderbird 22 and later. If you have set up the signature as an html document then the typeface to be used could and should be set by appropriate font tags. The courier-like font suggests it's just using defaults. I usually suggest that a signature be created by going through the motions of writing an email, i.e. start a new message, clear everything, and type your signature text (and add pictures) using Thunderbird's own formatting tools in the composition window. Then use '''File|Save As''' to save it as an html file, and nominate that file in the signature set-up under account settings. Or, for the slightly more ambitious, open that html file in a text editor and copy-and-paste the html coding into Thunderbird's signature text box in the account settings - but this does require some familiarity with the structure of the code. Myself, I use a variety of signatures (stored in html files) and the Signature Switch add-on to choose between them.