How big is the ornament?

About 65 to 80 mm across and 5 to 6 mm thick, with a hole at the top for a ribbon or hook.

How do I print it in two colours?

Print the STL and change filament when the print reaches 4 mm (the top of layer 20 at 0.2 mm). The letters and studs then come out in the second colour.

Do the studs fit real bricks?

They use standard brick-compatible sizes: 4.8 mm across, 8 mm apart. They are there for the look, so a brick may sit loosely on them.

Free brick-style Christmas ornament maker

Type a name and a year, pick a shape, and get a flat Christmas ornament with raised blocky letters and a row of brick studs. Turn it round in the preview, then download the STL to print. It all happens in your browser.

Trying it is free. Downloading needs a free account (just your email); Pro owners are not asked.

Printing it

Print it flat on the bed, letters up. It needs no supports.
Two colours with one nozzle: add a filament change (pause) at 4 mm, the top of layer 20 at 0.2 mm. Everything above it, the letters and the studs, prints in the second colour.
With a multi-colour printer, Pro owners can download a 3MF with the ornament and the letters as two parts, already coloured.
PLA is fine. Use 3 walls and 15% infill; a 0.2 mm layer height keeps the small letters sharp.
Thread a ribbon or an ornament hook through the hole at the top.