the yellow & purple are the actual caps.
Negative dye sub process. Dye sub around the legend.
Really interesting process and it seems to work fairly consistently down to the base of the caps, though it looks like they had trouble with the ISO return key inside the corner where the dye hasn't made contact.
I probably wouldn't be interested in a full keyset, but would definitely be interested in a purple mod pack, particularly 1.25 OS keys, ESC key, and Enter key. Would go great with the black/purple on beige Hangul set I recently bought through your site. Would mod packs or individual keys be a possibility before full keysets go ahead, to give people a cheaper option to see these caps for themselves?