MAC Siren Song is a moderately warm-toned, light beige with a metallic finish. It is a limited edition lipstick that retails for $21.00 and contains 0.1 oz.
MAC Siren Song Lipstick ($17.50 for 0.10 oz.) is described as a "sheer pale beige [with a Lustre finish]." It's a very light, champagne beige with a frosted sheen--pretty much as MAC describes it. The way this appears applied is going to depend greatly on your natural lip color, as it is semi-sheer. This shade lightens my natural lip color while adding warmth and gold shimmer. The color wore well for two hours, and it was lightly drying on me, which is typical of my experience with Lustres; worth noting, some readers find the Lustre formula very hydrating, others in the middle, and some, like me, drying, so if you generally find them hydrating, then I would be less concerned about the drying aspect of it. MAC Altered Beige (LE, $16.00) is darker, warmer. Giorgio Armani #111 (P, $32.00) is darker, more opaque. Buxom Nudist (P, $21.00) is more opaque, less shimmery. See comparison swatches / view dupes.
FURTHER READING: Formula Overview, which is a detailed review of the range as a whole.
Formulated to shade, define and showcase the lips, M·A·C Lipstick is available in every nuance of your favorite color and high-fashion texture. It's the iconic product that made M·A·C famous. AMPLIFIED CREME (A): Ultra-creamy. Quietly shiny. Color-packed! Hi-res: hi-impact. CREMESHEEN (C): Creme-based lipstick that imparts bright full color, with a soft and supple shine. FROST (F): Excellent color payoff with medium to high frosted shimmer-and-shine finish. LUSTRE (L): Demi-sheer with wet-look lustre finish. Very slick. Makes lips look soft, smooth, ultra-moist. MATTE (M): Pigment rich with intense color pay-off. No-shine, all matte finish. SATIN (S): Color-rich. Soft satin, semi-matte finish. Conditions while adding intense color.