hhkbp2I have this keycap set, but I am missing a few keys. I did some research from the product description page. This was designed by Jacob Rus. It looks like his original idea was spun on GeekHack. Seen here:
https://geekhack.org/index.php?topic=61558.0
The poster is also named Jacob, which I presume is the designer. In the forum he states the following, "Okay. How about this? (I’m trying to match SP’s PBT colors WFJ and BFE)". This is what lead me to the blue as BFE.
Anyways I'm going to order some arrows keys in BFE.