"`KORaroma06` is a seedling selection which resulted from the controlled pollination of an unnamed Rosa hybrida seedling developed and owned by the same inventor, the seed parent, with Rosa hybrida `KORpot028` (U.S. Plant Pat. No. 25,004), the pollen parent, during the summer of 2013.

From US Patent.


So it's an unknown x dark red miniature. I would guess something like Geoff Hamilton (or another similar Austin rose), or descended from, is the unknown half.