I would like to change the color or font of some names in my address book, and have that color or font show in the TO entry when I compose an email. The changed color or font would not appear in the email when it is sent, only when I am composing the email. I would like to have this because as I type the start of an email address in the TO box, several choices appear, and a few times I have accidentally clicked the wrong choice and sent the email to the wrong person. If I differentiated email addresses, say one color for family members, another for friends, a third for colleagues, etc., I would be less likely to make this mistake. I have set up Thunderbird so that for selected email addresses the sender and subject are in a different color on the main page that shows received email. But I haven't found a way to have different font colors for the recipient address when composing email. Is there a way to do this?