Tom Ford Beauty Siren Blue is a very cool-toned, dark aqua with a metallic finish. It is a limited edition eyeshadow that retails for $45.00 and contains 0.17 oz.
Tom Ford Siren Blue Cream Color for Eyes ($45.00 for 0.17 oz.) is a medium-dark, aqua blue with cool undertones and a metallic sheen. It had good pigmentation with a creamy consistency that had a wetter feel than most shades I've tried in this formula. The dry down took longer, and it was hard to keep from gathering in the creases when I tried using it on my inner corner/lid area; when I tried it on the outer lid, I had less trouble. Once it set, I didn't get further creasing or movement until eight and a half hours later.
Milani Bella Teal (21) (P, $4.49) is brighter (90% similar). NARS Inception (LE, $19.00) is lighter (90% similar). Lancome My French #7 (LE, ) is lighter (90% similar). Makeup Geek Pegasus (P, $9.99) is warmer (90% similar). Marc Jacobs Beauty The Siren #5 (LE, ) is less shimmery, warmer (90% similar). Marc Jacobs Beauty Shoshanna (414) (P, $28.00) is lighter (90% similar). Anastasia Venice (P, $12.00) is more shimmery, lighter (90% similar). Coloured Raine Malibu (DC, $6.99) is more shimmery, cooler (90% similar). CoverGirl Turquoise Glow (325) (LE, $4.99) is lighter (85% similar). Fenty Beauty Cosmic Ocean (LE, ) is lighter (85% similar). theBalm Big Kahuna (LE, $16.00) is warmer (85% similar). Sydney Grace Dive (P, $6.00) is more shimmery, warmer (80% similar). ColourPop The Pisces (P, $4.50) is lighter (80% similar). Chanel Griffith Green (126) (LE, $32.00) is darker, warmer (80% similar). Lethal Cosmetics Mirage (P, $6.00) is more shimmery, lighter (80% similar). See comparison swatches / view dupes side-by-side.
FURTHER READING: Formula Overview, which is a detailed review of the range as a whole.