I bought this polish when I was living in Yokohama, Japan. It is very beautiful. Has a very mermaid quality to it. It applies and dries very nicely. It is a light blue hue with a light yellow undertone. The only problem I have with it, is it is a very hard color to wear. It doesn't go well with many things that I wear. However, I love to look at it and am happy to add it to my polish collection. If you are an OPI collector, love to wear unique colored nail polishes Baby Blue is a must have. If not...then it is probably a pass.
My bottle of Baby Blue has the old formula, so it applies very nicely. At one coat it's a faint blue with a beautiful golden shimmer. Looks especially nice when the afternoon sunlight hits it, it looks green. If you like/don't mind VNL and can apply polishes with one coat evenly, then I would recommend only one coat. You can also layer it over a light blue jelly to keep that delicate look. At two coats the polish becomes almost a duochrome and base looks more white and frosty. Otherwise, I would probably layer it over a similarly-colored blue creme to keep it's delicate look without the frosty look.
OPI Baby Blue is from the Asia-Australia exclusive Yokohama Collection. It is a pretty sheer colour, 3 coats to reach opacity, but applies well. It is a pale blue colour with a green 'glow' and it also shines gold when it hits the sunlight. It is a very unique colour! I purchased it at David Jones for $20AUD. I don't think it would suit extremely dark skin.