They weren't "Colorforms" in the eighties, but a similar thing (hesitant to say "knockoff") called Stick 'n Lift. I wonder why, since Colorforms made the Lazer Blazers, which did have ponies... The Stick 'n Lift set seems pretty early (Blossom, AJ, etc. were included and the art style is an earlier one), so perhaps they weren't interested in the license at first? I dunno.
Here's where I'd give you the link to the commercial, but I just couldn't find it! It has a song with the melody of "Turkey in the Straw," and while Pony takes center stage, the commercial also shows a Charmkins set and one for the Chipmunks. What a shame, it was pretty cool. Ah well.
If you want the lyrics, I remember some of them:
Spoiler
You can stick a Little Pony over here or over there
You can stick a little flower in your Little Pony's hair
You can lift your pony up and then stick her down again
Under the apple tree or right outside the pen
EDIT: Didn't see the post above. Apparently it wasn't Blossom, but Medley. Don't ask how I got that mixed up... She was the pony who got the flower in her hair, so that could be it. There was apparently an earlier kit though (seen on My Little Wiki), in an earlier art style with Seashell, Firefly, etc. so who knows? I don't remember the commercial clearly enough; I only watched it a few times when it was on YouTube (where it appears to no longer be!) and couldn't tell you.
As for these new ones, I'm happy to see the inclusion of ponies you don't see as often. I mean, what retro merch has TAF Yum Yum or Daisy Sweet (albeit lacking her puffy hair), let alone BOTH? The former is my favorite TAF pony, and with Starshine and June Rose (my birthflower), I really like this set. I find them a bit expensive, though.