Photo by Cdurfor

FUNDRAISER: Former American Idol winner Adam Lambert headlines a fundraiser at the 9:30 Club (815 V Street NW) on behalf of Marylanders for Marriage Equality, the organization that is supporting a ballot measure that would uphold Maryland’s recently enacted law approving same-sex marriage. Show begins 7 p.m. Tickets $125-250, available at 930.com.

COLOR SPIEL: Regina Lee Blaszczyk, a history professor at the University of Pennsylvania, signs copies of her new book The Color Revolution (MIT Press, $34.95), which explains why that color you just have to have came to prominence. From the book jacket, it’s not because of anything Anna Wintour said. At 8:45 p.m. at the National Museum of American History (1300 Constitution Avenue NW).

DRUNK BATTLESHIP: The new bar Board Room (1737 Connecticut Avenue NW), which features a library of classic board games to accompany its menu of cocktails and snacks, opens today at 4 p.m.

ATONEMENT: Yom Kippur, the holiest day on the Hebrew calendar, begins tonight, with a day-long fast and many hours in synagogue making amends for misdeeds committed in the year 5732. Begins at sundown at 6:59 p.m.