On the main Ravelry page, select the Yarns tab. In the search yarns box, type in Knit Picks Risata and click the Search button. Select Risata; this will display the yarn detail page. Scroll to the bottom of the page where the Popular Colorways are listed. Look for your colorway (Woodland Sage). I believe there are two listed (don't know why). On the first one, select "106 stashed". This will take you to a listing of memberswho have this yarn colorway in their stash. The first member stash listed on the page (rkrueg) lists your lot number and indicates this member is willing to sell or trade their stash of this yarn. (I've linked to the members stash page for you but thought I'd give you instructions for future searches.) To send this member a message re: the yarn, click the envelope to the right of the picture of their stash where it says "Will sell or trade".
FYI - There's also a group you can join called In Search of Yarn (Trading, Swapping, Selling) where you can post requests if you ever need to find a yarn in the future.