The RETRO style looks a lot like the ODT guy's "SoWaRe" key caps, that were colour-mismatched replicas of WYSE key caps.
Are the light and dark key cap base colours of the RETRO style compatible with either SoWaRe or WYSE caps?
The dark grey ("GQM") in the wiki
looks too dark compared to the darker keys on my WYSE keyboard, but it could be just the photo. (I don't have any SP colour samples ..)
If they do match, then I am thinking of getting some RETRO/RGBY caps as a kind of "Moogle kit" for using my WYSE caps on a keyboard with classic PC layout.