After researching this, it appears Thunderbird doesn't have native settings or prefs, to change the compose window background or text colors, <strong>without</strong> also sending those colors in outgoing html mail? That seems like it'd be a standard feature, but so do a lot of other things. Like Tb, many email clients have settings to not use the sender's message colors or named font. Some users don't have that enabled. I'm afraid if I compose w/ dark background & light text, they may miss some things. Like if their links default color is too close to a dark BG, etc. Does anyone know of a CSS or other solution to this issue? Have the outgoing html messages use standard dark text on light BG, when the composing window is opposite of that? I guess one, not as handy solution is use an external editor, then copy to a Tb compose window that uses default colors.