WISE color–color diagram for the Keck Nonmerger Comparison Sample, shown relative to the parent Galaxy Zoo merger population (f_m > 0.4; shaded contours). The crimson squares denote systems with detected NIR substructure, and the blue points indicate systems without detected substructure. The horizontal dashed line marks the W₁ − W₂ > 0.5 AGN color selection threshold (L. Blecha et al. 2018), and the dashed box indicates the AGN selection wedge from T. H. Jarrett et al. (2011). This figure shows that the Keck Nonmerger Comparison Sample occupies a similar region of MIR color space as the Primary Keck AO Merger Sample, enabling a direct test of whether SDSS/WISE positional offsets alone can identify systems with unresolved NIR substructure.