Go to Back Room of the Brothel (#29922) on Main Street, west and south of Recall, and kill Rasputin until you get 'a cut gemstone', then go to Captain's Quarters (#30124) on the Pirate Ship in Treasure bay and kill the captain for a 'a silver band'.
Then goto the Ring Shop (#29917) 1 west and north of Town Square on Main Street and give the band to Holton the ring crafter. Holton will give you 'a crafted ring band', look at the ring and either click the artifice button or type "artifice a multi-colored ring" with both the crafted ring band and the cut gemstone in your inventory to make the multi colored ring.
If you mess up and give something to Holton you shouldn't have you can always kill him as he is not protected.