Then, have your sim interact with the umbrella rack and select the “Take an Umbrella” option. This will equip them with a default black umbrella that they will automatically open and use when it rains outdoors. The umbrella does not show up visibly in their inventory.
You can customize the umbrella’s color and pattern. Simply click on your sim while they have the umbrella buff, and choose the umbrella in their outfit category. There you can pick from a selection of colors and patterns. Different umbrella custom content mods add more options too.
The umbrella stays with that specific sim until they put it back in the rack. So you only need one rack to supply umbrellas for an entire household if each claims one.
Robots and NPC sims may also autonomously grab umbrellas from racks when going out in the rain. Some mods can tweak or disable this umbrella autonomy if it is unwanted.
So in summary, buy an umbrella rack, have sims take umbrellas from it, customize umbrella appearance, and manage autonomy with mods if desired. Let me know if you need any clarification or have additional questions!