Colors to dye for: Palladium‐catalyzed regiospecific N‐heteroarylations of amidines with 2‐halo‐N‐heteroarenes leads to a structurally diverse library of BF2/amidine‐based complexes. These dyes not only present full‐visible‐color solid‐state emissions with large Stokes shifts and high fluorescence quantum yields, but also exhibit a full‐color‐tunable mechanofluorochromic nature.