Comparison of H- and K-band power-law coefficients from CHARA data and atmosphere-model predictions. The filled colored points show the empirical CHARA coefficients, (α_H, α_K), measured by fitting the CHARA V² data and color-coded by T_eff. The gray sequences show the corresponding model-grid predictions. Left: direct intensity-domain model coefficients, ﹩({\alpha }_{I,H}^{g},{\alpha }_{I,K}^{g})﹩, obtained by fitting the analytic law to the passband-integrated model intensity profiles I_b(μ) (Section 4.3). Right: SVAM coefficients, ﹩({\alpha }_{{\rm{SV\; AM}},H}^{g},{\alpha }_{{\rm{SV\; AM}},K}^{g})﹩, recovered by fitting the same law to synthetic CHARA-sampled visibilities generated from each model CLV (Section 4.4). The dashed line marks equality between the H- and K-band coefficients. The systematic separation between the colored CHARA and the gray model points shows the model–data discrepancy discussed in the text.