One way to make the room get an warm welcoming light, is to recreate sunlight in Unity. This can be done by clicking on GameObject → Light → Directional Light where a new light source will appear. If you would like to add shadows, choose a Shadow type in Inspector. Relocate the light source and adjust the direction as you wish by rotating it. The direction of the light source is pointing along the z-axis. In order to see the effect of the changes in real time, unclick the Continious Baking box.