A decoration member comprising: a color developing layer including a light reflective layer and a light absorbing layer provided on the light reflective layer; and a substrate provided on one surface of the color developing layer and including a pattern layer, wherein the pattern layer includes a convex portion or concave portion shape having an asymmetric-structured cross-section, a prism structure, or a lenticular-lens structure, wherein: the light absorbing layer consists of silicon (Si); and a cool tone parameter σ represented by Equation 1 is greater than 0 and less than or equal to 0.7: σ = T x × T y wherein: - T x is 1, if T 1 = m × T 0 + 10 nm, m being an integer, - if not, T x is determined according to Equation 2: Tx = T 1 − 10 nm + T 0 − T 1 − 10 nm + T 0 T 0 × T 0 × T 0 − 1 Ty is represented by Equation 3: Ty = T 2 + 5 × T 0 5 × T 0 in Equation 2, T 1 − 10 nm + T 0 T 0 is a maximum integer that is not greater than T 1 − 10 nm + T 0 T 0, T 0 is 60 nm; T 1 is an average thickness of the light absorbing layer included in one cross-section in a thickness direction of the decoration member, and T 2 is an average thickness of the light reflective layer included in one cross-section in a thickness direction of the decoration member, wherein the thickness T 1 of the light absorbing layer is 10 nm to 300 nm, wherein the thickness of the light reflective layer is 1 nm to 100 nm, wherein T x is greater than 0 and less than or equal to 0.5 when determined according to Equation 2, wherein T y is greater than 1.0 and less than or equal to 1.4. a color developing layer including a light reflective layer and a light absorbing layer provided on the light reflective layer; and a substrate provided on one surface of the color developing layer and including a pattern layer, wherein the pattern layer includes a convex portion or concave portion shape having an asymmetric-structured cross-section, a prism structure, or a lenticular-lens structure, wherein: the light absorbing layer consists of silicon (Si); and a cool tone parameter σ represented by Equation 1 is greater than 0 and less than or equal to 0.7: σ = T x × T y wherein: - T x is 1, if T 1 = m × T 0 + 10 nm, m being an integer, - if not, T x is determined according to Equation 2: Tx = T 1 − 10 nm + T 0 − T 1 − 10 nm + T 0 T 0 × T 0 × T 0 − 1 Ty is represented by Equation 3: Ty = T 2 + 5 × T 0 5 × T 0 in Equation 2, T 1 − 10 nm + T 0 T 0 is a maximum integer that is not greater than T 1 − 10 nm + T 0 T 0, T 0 is 60 nm; T 1 is an average thickness of the light absorbing layer included in one cross-section in a thickness direction of the decoration member, and T 2 is an average thickness of the light reflective layer included in one cross-section in a thickness direction of the decoration member, wherein the thickness T 1 of the light absorbing layer is 10 nm to 300 nm, wherein the thickness of the light reflective layer is 1 nm to 100 nm, wherein T x is greater than 0 and less than or equal to 0.5 when determined according to Equation 2, wherein T y is greater than 1.0 and less than or equal to 1.4. the light absorbing layer consists of silicon (Si); and a cool tone parameter σ represented by Equation 1 is greater than 0 and less than or equal to 0.7: σ = T x × T y wherein: - T x is 1, if T 1 = m × T 0 + 10 nm, m being an integer, - if not, T x is determined according to Equation 2: Tx = T 1 − 10 nm + T 0 − T 1 − 10 nm + T 0 T 0 × T 0 × T 0 − 1 - T x is 1, if T 1 = m × T 0 + 10 nm, m being an integer, - if not, T x is determined according to Equation 2: Tx = T 1 − 10 nm + T 0 − T 1 − 10 nm + T 0 T 0 × T 0 × T 0 − 1 Ty is represented by Equation 3: Ty = T 2 + 5 × T 0 5 × T 0 in Equation 2, T 1 − 10 nm + T 0 T 0 is a maximum integer that is not greater than T 1 − 10 nm + T 0 T 0, T 0 is 60 nm; T 1 is an average thickness of the light absorbing layer included in one cross-section in a thickness direction of the decoration member, and T 2 is an average thickness of the light reflective layer included in one cross-section in a thickness direction of the decoration member, wherein the thickness T 1 of the light absorbing layer is 10 nm to 300 nm, wherein the thickness of the light reflective layer is 1 nm to 100 nm, wherein T x is greater than 0 and less than or equal to 0.5 when determined according to Equation 2, wherein T y is greater than 1.0 and less than or equal to 1.4.