Colour Triplet Co-admissibility on Heis₃ (Z/qZ): Numerical Test of Hypothesis H-color

We report numerical evidence for Hypothesis H-color (colour triplet co-admissibility) on the Heisenberg group Heis₃ (Z/qZ), the key open condition in the derivation of SU (3) as the admissible gauge group of the colour sector. For a prime q 1 3, a colour triplet is a set \c₁, c₂, c₃\ (Z/qZ) ^* satisfying c₁ + c₂ + c₃ 0 q and pairwise non-conjugacy. H-color asserts that the three BFS capacity profiles ₂䃑 (n), ₂䃒 (n), ₂䃓 (n) are equal in the pre-saturation window, i. e. \ that the three sectors are co-admissible. The test observable is the inter-triplet variance ratio Rₕ₀ₑ = Var₈ (₂_₈ (n) ) / ₂_₈² (n), normalised against the intra-pair variance of conjugate pairs \c, q-c\ (known co-admissible by O25) as a noise-floor reference. We find Rₕ₀ₑ 3. 4 10^-3 at q = 61, 7. 1 10^-4 at q = 151, and 1. 6 10^-3 at q = 211, all at or below the noise floor ctrl\ᵣef = 3. 81 10^-3 (calibrated from controls q \29, 101\), consistent with exact co-admissibility up to block-sampling variance. The triplet capacity exponent satisfies ₓₑ₈ 3c at all three primes, confirming the additive structure predicted by O31. All triplet covariance matrices C₂₎₋₎ₑ End (V₂₎₋₎ₑ) have numerical rank 1. We additionally prove that the block-averaged capacity profiles satisfy Ec (n) = E ₂ (n) + O (q^-1) analytically (Proposition prop: avg-hcolor), establishing H-color₄₅₅ (equality of capacity exponents) in the q limit. The observed decrease of Rₕ₀ₑ with q is interpreted as the finite-q modulation bias predicted by this argument, with expected scaling Rₕ₀ₑ q^-1. Results for q = 307 are pending.