The 4–5 μm color of 29 Cyg b in context. (a) A deconvolved and smoothed three-color composite. Blue is assigned to the F410M filter, green to the F430M filter, and red to the F460M filter, in increasing wavelength; the brightness in each filter is in units of MJy sr^–1, normalized to the brightness of the companion in F410M. The location of 29 Cyg A, blocked by the LWBAR/narrow coronagraph, is marked by a cartoon star. (b) Color–color diagram of brown dwarfs and giant planets between 4 and 5 μm. 29 Cyg b exhibits striking similarity with HR 8799 c and e, which are offset toward deeper CO₂ absorption from the brown dwarf population. The typical uncertainty for the BDs is 0.03 mag, smaller than the scatter points.