Shiny surfaces reflect more light and therefore are less radiant compared to dull finishes. I remember that shiny white is the most reflective of light and radiates the least heat. That is to say how much the surface radiates. If it is hot or cold, so is the surface. I guess what you are considering is the absorption of heat. The lighter and more shiny surface reflects the most light and the material surface matches the environmental temperature (equilibrium) so it would transfer less heat in the winter and summer but it would still match the outside temperature. Insulation is key.
2015 Ford F-150 3.5 Ecobeast 3.55 Lariat