The color of a transition metal complex with a tetrahedral geometry depends on the specific metal ion and ligands involved in the complex. The color arises from the absorption of light by the complex, which promotes an electron from a lower energy d-orbital to a higher energy d-orbital. This energy difference between the two d-orbitals is known as the crystal field splitting energy .In a tetrahedral complex, the crystal field splitting energy is generally smaller than in an octahedral complex due to the different arrangement of ligands around the metal ion. As a result, the absorbed light's wavelength and thus the color observed may be different for a tetrahedral complex compared to an octahedral complex with the same metal ion and ligands.To determine the color of a specific tetrahedral transition metal complex, one would need to know the metal ion, the ligands, and the crystal field splitting energy. The color observed is complementary to the color of light absorbed by the complex. For example, if the complex absorbs green light, it will appear red.