Guerlain Rouge G Lip Color ($32.00 for 0.12 oz., refill only) launches exclusively on Sephora on April 10th and will be at all other retailers on May 1st, though the launch is available at global retailers already. I bought 29 shades from Selfridges, but they were, unfortunately, already sold out of #62. Oddly enough, the cases will not ship the US via Selfridges, so I actually did not have a chance to purchase any cases but will pick one up when they launch in the US.
Per Guerlain, the formula itself has not changed, just the way the packaging comes together and how the two are purchased. I did not notice anything different upon initial swatching. There may be some shades that are repeated from the original range in the new one, but I did not find that most of the numbers (the original range had names and numbers) lined up with the new range.
Each refill comes with a plastic cap to keep the refill from drying out (remember, they’ll have to sit in the box until purchased), so purchasing an actual case doesn’t seem necessary. The previous Rouge Gs retailed for $54 and contained 0.12 oz., whereas now you can get the formula for $32.00 for 0.12 oz. or $47.00 for 0.12 oz. with case–significantly cheaper than the $54 all-in price from before.