I found this recipe on liquor.com.

gin, sweet vermouth, Chartreuse, Campari⁣
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This is a pre-Prohibition era drink that largely disappeared after Prohibition. It was invented by the “father of professional bartending”, Harry Johnson. ⁣
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The name is very cute. “Bijou” means “jewel” in French. Harry named it bijou because it combined the colors of three jewels: gin for diamond, vermouth for ruby, and chartreuse for emerald. Love it.⁣
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It is a yummy drink, with a lot of flavor. To my palette, you can put a drink like Lemon Drop at one end of the “pow flavor” spectrum (tasteless, aside from tart and sweet), and drinks like this at the other end (a little sweet, a little bitter, a little herby, bit of gin bite coming through). “Complex”, I think is the right word. ⁣
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I bought the necklace in this photo at a store called Bijou, which made me think of using it in the Bijou cocktail photo, naturally.⁣