Reddit mentions of ICED Enamels ICE Resin Amethyst, 15 ml/.5 fl. oz.

Ok, so these are two totally different processes. My guess is your only option will be cold enameling. It’s basically a pigment in resin, like this

Mix it according to package directions and fill your embossed regions using a dowel rod, metal tool or whatever fits best. Even a disposable pipet would work well. The resin hardens at room temp. Issues can include swirl marks on the surface, so practice applying to scrap pieces first. This is a really pretty easy process with minimal tools needed. It’s not a “traditional” process though, and definitely not regarded as “fine jewelry”. Edit to add: your metal must be extremely clean before applying resin. Grab a toothbrush and scrub it up with dawn dish soap (sometimes diluted with ammonia). Pumice powder is also an excellent cleaner. I gotten finish with a rubbing alcohol wipe as well.

Vitreous enameling is a very traditional process, and it’s very fussy. Glass melts at a higher temp than solder flows at, so for one thing you cannot solder a piece together and then enamel it (unless you use IT solder). Thompson enamel is the industry standard brand, available through rio grande. Your metal surface must be impeccably clean first, and generally pure metals are best (copper, fine silver, 22k gold. Not 14k, brass or sterling though).

There are many enameling techniques, but the most basic application is to sift the powdered glass through a tiny sieve onto a metal surface. Other techniques include wetting the powder and then packing it into cells (google search champleve or cloisonné). The piece is placed into a hot kiln (around 1450 deg) for a few minutes until the glass particles melt and fuse together. There are additional finishing processes necessary after firing, especially in champleve and cloisonné to perfect the surface. There are other processes and techniques I’m not going to discuss here. Enameling is a very fussy, tedious process which requires a lot of forethought (no soldering, so assembling a piece has extra challenges) and specialty tools like a kiln.

Hope that clarified the two processes and gave a little insight into enameling! It’s a process I love and am happy to answer any more specific questions you might have.