I really liked the coloring, and I wanted to preserve that feel. I could have made two stamps and gone for the multi-impression stamping, but as my experiments with the sakura showed, it is quite hard to get a clean two-color stamp. Clearly, some other way was needed.
The solution was to futz a bit in GIMP, and I ended up with an image where all the white lines in the original (the outlines of the colored spaces) were black and the rest was white. I cut a stamp from that, so that I could get the outlines I wanted:
A huge close-up of the original stamp. It's 8 x 8 cm, like most of the large bee_eye stamps I made. It was a bit finnicky, but overall pretty nice to do.
After that, klik took up the markers and started coloring:
Turns out that the markers bleed through the paper I use for cards, which made writing them a bit iffy. Still, I'm very pleased with how they turned out!