This will give you a pop up that will browse to your.

package and want to add more recolors to the item you can open it up again using My Projects. Instead of seeing any EA original recolors you will only see your single texture replacement. In the game you will see a default replacement if you select the original item. Since this is best used for things like eyes I cloned the amber eye for this example. The last kind of recolor is a Replacement CAS Part. You can see my standalone recolor right next to the EA original catalog entry. All of the original color choices are still there but there are also my two new ones - the pink and the green ones. On the right you can see the original EA top that I cloned with it's swatch thumbnails box open.

The picture below shows the front screen with Add CAS Part Swatch selected on the left. Instead you will be able to add new recolor options to an EA item.

If you choose Add CAS Part Swatch you will not get a new catalog entry. A standalone item will not change the original EA catalog entry in any way. Note the original EA shirt is next to the new one. On the right is the new Standalone catalog entry for the garment and the two new swatch thumbnails showing it has two color choices - green and pink. On the left side of the picture below is the first screen with the Standalone CAS Part button selected. In the game if you select Standalone CAS Part you will get a completely new catalog entry for your recolor and the only colors it will have are the ones that you added to it. When I had added the two new swatch thumbnails and Textures the screen looked exactly the same no matter which option I had chosen from the first screen: This is the shirt and you can see it has a pink swatch thumbnail for the pink recolor and a green swatch thumbnail for the green recolor. I cloned the same top for both and used the exact same textures to recolor it - a pink one and a green one. The first by choosing Standalone CAS Part and the second by choosing Add CAS Part Swatch. For these two I made two separate clones. The first two types are selected as Standalone CAS Part and Add CAS Part Swatch. This mini-tutorial will show what each of these is called and what you end up with in the game if you make that kind of recolor. There are three different types of CAS recolors that you can make with Sims 4 Studio.

Sims 4 nantouch trash can recolor