[NiCl₄]^2– and [Ni(NH₃)₆]²⁺ have different colors because the splitting energy (Δ) of [NiCl₄]^2– is greater than the splitting energy of  [NiCl₄]^2–. [NiCl₄]^2– will absorb at longer wavelengths.

[NiCl₄]^2– and [Ni(NH₃)₆]²⁺ have different colors because the splitting energy (Δ) of [NiCl₄]^2– is smaller than the splitting energy of  [NiCl₄]^2–. [NiCl₄]^2– will absorb at longer wavelengths.

[NiCl₄]^2– and [Ni(NH₃)₆]²⁺ have different colors because the splitting energy (Δ) of [NiCl₄]^2– is greater than the splitting energy of  [NiCl₄]^2–. [Ni(NH₃)₆]²⁺ will absorb at longer wavelengths.

[NiCl₄]^2– and [Ni(NH₃)₆]²⁺ have different colors because the splitting energy (Δ) of [NiCl₄]^2– is smaller than the splitting energy of  [NiCl₄]^2–. [Ni(NH₃)₆]²⁺ will absorb at longer wavelengths.