I figured that.
ASaffron had the idea that maybe its a rare type inter-species hybrid where the dominant gene are Hylocereus undatus but the skin comes out yellow.
Meanwhile, my 'blue' DF (Hylocereus bronxensis) order came the other day:
And the Pineapple Cactus (Selenicereus setaceus) Thao sent me is jamming already:
And my Sword Pear (Acanthocereus tetragonus) hand pollination attempt appears to have worked:
Can't wait until next year I'll be doing all kinds of crazy
xcereus hybrid attempts...