This is based off of stormi's "Global dark style - changes everything to DARK," but I've been playing with this for a while and could be miscrediting and/or leaving out others. [Global dark style - changes everything to DARK/global-dark-style-changes-everything-to-dark] This also seems to with KemuelDam's "YahooMail (Ajax) - Truly adfree means no adbar." [YahooMail (Ajax) - Truly adfree means no adbar/yahoomail-ajax-truly-adfree-means-no-adbar]

NOTE: This style causes the text color selection palette in Yahoo! Mail to not display properly, so it's easy to accidentally select a color and not realize it because the script overrides the font color displayed on your screen. This minor problem is easily avoided by not pressing the color button. If you really need to change the color of your text, it's best to temporarily turn off this script while you are writing/editing your message.