As seen on Survivor 46 (Episode 2) (and a similar puzzle on Survivor 45 (Episode 11)). When correctly solved, the word “PERSISTENCE” can be read from both sides of the arch.
I was able to print without supports as long as I was printing black letter/white background side down - this minimizes bridging on the first color change.
In order to get the different colors on the blocks, I printed with the black letter/white background side facing down on the build plate, and added filament changes before Layer 6 and Layer 80. Since I'm using Cura UltiMaker, that meant adding “Pause at Height” post-processing scripts at layers 5 & 79.
For the puzzle base, I added a filament change before Layer 10 ("Pause at Height" script at layer 9 in Cura).
The author marked this model as their own original creation.