Paramagnetic and coloured ions are :

Gd belongs to lanthanoids and electronic configuration in Gd³⁺ state is $\left[\mathrm{Xe}\right]4f^7.$ Electronic configuration of Nd³⁺ is $\left[\mathrm{Xe}\right]4f^3.$ Because of having unpaired electrons, both Gd³⁺ and Nb³⁺ are paramagnetic and imparts color.