[Boxxxed]

In a coordination complex will a higher positive charge on the cation increase or decrease the energy needed to excite electrons in the 3d orbitals?

If the cation is more positive I would assume it would attract the 3d electrons causing an increase in the energy required to excite them to higher orbitals. Is this correct?

[DevaDevil]

yes, a higher oxidation state leads to larger d-orbital splitting