A resist is something that prevents dye from reaching selected parts of a textile. In àdìrẹ oniko, tight bindings create protected areas; in alabare, stitching performs that role; in eleko, makers apply cassava-starch paste. These names describe processes, not three universal sets of motifs. A cloth may also combine approaches.
The distinction from an indigo-colored print is therefore about making, not a competition between attractive and unattractive fabric. A printed textile can reproduce the appearance of tied circles or painted compartments without passing through the same sequence of preparation and dyeing. Conversely, a machine-woven cotton ground does not disqualify hand-worked àdìrẹ: makers have long transformed purchased cloth through their own labor.
Indigo blue is an important historical reference, not a rule that exhausts the practice. The Horniman's account describes the expansion of àdìrẹ into other colors and wax-resist methods. Ask which technique and dye were used on the particular piece before deciding that unfamiliar colors must indicate a fake. The useful question is whether the description accurately represents the work.