Color–color diagram of L′–NB4.05 vs. NB4.05–M′. Synthetic colors are calculated from the AMES-Cond (T_eff = 150-3000 K), AMES-Duty(T_eff = 500-3000 K), BT-Settl (T_eff = 400-3000 K), DRIFT-PHOENIX (T_eff = 1000-3000 K), petitCODE cool (T_eff = 150-1000 K), and petitCODE hot (T_eff = 1000-2000 K) atmosphericmodels (colored lines) across the indicated temperature range. The other parameters have been fixed to log g =4.0 dex, [Fe∕H] = 0.0 dex, C∕O = 0.55 (only petitCODE), and f_sed = 2.0 (only petitCODE cloudy). The dots decrease in size towards higher temperatures and correspond to 150, 300, 400, 500, 750, 1000, 1250, 1500, 1750, 2000, and 3000 K. The directly imaged companions for which photometry is available in the three filters are shown for comparison. The blue and red shaded regions indicate approximately two different NB4.05–M′ regimes.