Here's a quick post of how Chanel's Nail Colour in Bleu Pastel (584), which is a new permanent shade released as part of the "Énergies et Puretés Collection"(swatches, photos and details of the entire collection can be found here). I actually purchased this shade as I love it, but exchanged it as soon as I realised I already have one that was pretty much the same shade! >_< See below for comparison swatches). Here's how it looks against my medium to tan, olive (~NC30-35) skin tone [photographed indoors using a strobe]. I applied about two coats without a base or top coat. Bleu Pastel is exactly as it translates in English - pastel blue! To my eye there is no shimmer and it is quite glossy in finish.
Comparison Swatches
Below are comparison swatches of the pastel blue nail polishes in my collection (I realise I have one too many! >_< LOL. Such is life of a beauty blogger. ;-) ). These are photographed indoors using a strobe.
As you can *hopefully* see below, Chanel's Bleu Pastel is almost identical to Dior's Porcelaine(204) - up close, the former is just ever so slightly lighter and brighter, but the difference is pretty much negligible! Dior's Bleuette (301) is warmer and a touch less opaque and Chanel's Riva is noticeably sheerer, warmer (more yellow-toned) with subtle shimmers.
Most Chanel nail polishes I've tried have lasted excellently in terms of wear (among the longest actually compared to other brands), so I highly recommend them and this particular shade if you're after a pretty pastel blue. This one applied with full coverage (in a couple of coats), evenly and smoothly without any issues! :-)
Hope this was helpful.
Bon Week-end! ^_^