Which of the following statements is incorrect?

Observed color of the complex is the color of the absorbed light/wavelength

The correct answer is Option (3) → Observed color of the complex is the color of the absorbed light/wavelength

Explanation (based on crystal field theory and color in coordination compounds):

• When white light falls on the complex, some part of it is absorbed: Correct. d-d transitions absorb specific wavelengths from visible light.
• Higher the crystal field splitting, lower will be the wavelength absorbed by the complex: Correct. Larger crystal field splitting energy (Δ) requires higher energy photons, which correspond to lower wavelength (E = hc/λ, so higher E → lower λ).
• Observed color of the complex is the color of the absorbed light/wavelength: Incorrect. The observed (transmitted/reflected) color is the complementary color of the absorbed light. Example: If a complex absorbs green-yellow light (~550–600 nm), it appears violet/purple (the complementary color), not green-yellow.
• In the absence of ligand, compound is colourless: Correct. Without ligands (or with very weak field ligands like in gaseous/free ions), d-d transitions require very high energy (UV region), so no visible light is absorbed → the compound appears colourless.