I've put together some quick and dirty swatches of some of the colors I have from their collection. Some are part of the core line, some are new, hopefully you can still get all of these at your local Walgreens, if you want to.
Ocean Side, a marine blue:
Rain Storm, like a dark storm cloud (one of my new faves!):
Lavender. just like it says. This is a new color, I believe.
Savage. A matte turquoise blue:
How the blues compare to each other (from L to R, Savage, Lavender, Rainstorm, Ocean Side):
Some metallic-y blues. This is Ciao Bella:
Blue By You, a blue with green shimmer:
On to some pinks and reds. This is Forget Now, a magenta with glass fleck:
Bali Mist is too sheer to wear on its own, but turns Georgio into a lavender frost.
Dancing Nails is a metallic rosy pink:
Fig is another new color, but apparently bears some resemblance to OPI Plugged in Plum:
Georgio is a vampy red leaning brown. To me, it applies like a crelly. This is only one coat, but you can see where a bit of overlap darkens the color from brick red to almost a dried blood red color.
Some greens. This is HD Nails. It's fairly sheer, but builds up in 3 coats. Lots of shimmer in this one.
Rise and Shine is a matte sea-green, maybe jade-like color. It's not as blue as it looks in the pix.
Another new favorite, Leap Flog. I don't know why Sinful Colors spelled it that way. Must be an inside joke. It's a beautiful, murky grey-green.
When I swatched it, I thought it looked like Nicole OPI Green Up Your Act, and it's pretty close.
Not an exact dupe, but bears a strong resemblance - in this light, it looks the same. I'm glad, because I love the NOPI, and it was a Target exclusive, so rather than hunt down that color again, I just got a dupe for 99 cents. WIN!
Envy, a beautiful true green:
Last Chance, a jelly forest green. Most of these swatches are one coat, and here you can see the squishy texture of this color. 2 coats would likely be enough.
The greens together for a comparison. Last Chance on the thumb, and L-R is Envy, Leap Flog, Rise and Shine, and HD Nails.
Now for some neutrals. First up is Nirvana. This was only one coat, but it could have used two. It's a taupe leaning tan.
This is Winterberry, which is either a new color, or an older color brought back for a new spin. It's a purple-leaning taupe with a frosty shimmer.
Slate is apparently another older color that was HTF brought back for the season. It's a beautiful light grey with a shimmer.
Secret Admirer is a textured metallic charcoal grey. It's not a glitter, though. It reminds me a bit of China Glaze Stone Cold.
All together now. L-R Nirvana, Winterberry, Slate, and Secret Admirer.
Some that I couldn't fit anywhere else. This is Unicorn, a pale buttercup yellow. This is one thick coat. Not bad for a pastel yellow, the notoriously most finicky of colors.
Vacation Time. The most neutral .... well, neutral. A vacation from what, I wonder? This color is like a staycation on the couch. Comfy, but not very exciting.
Cloud Nine, a delightful surprise. Orange jelly packed with shimmer.
Let Me Go, another color too sheer on its own, turns Rich In Heart to a frosty green.
Rich In Heart on it's own. Another vampy red, but this one is much more wine colored, and with a glow from within.
Rich In Heart on the thumb, and RIH with Let Me Go on the index, Cloud Nine on the middle, Vacation Time on the ring, and Unicorn on the pinky.
I already many of the glitters, but I picked up a few more today. All of these are layered over Vacation Time. This is All About You, a gold microglitter in a clear base.
I Miss You. Purple and pink microglitter in a lavender base.
Pinky glitter - pink and holo glitter in a pink base.
Kinda neat how the three glitters make Vacation Time look like three different colors.
There are other colors available in the sale, of course. Hopefully this little guide will help you find some that you want to pick up before the sale is over. Happy shopping!