Relationship between layers and styles

[AndyKubrin]

I'm creating a map with about 20 locations marked by pins. To distinguish among groups of locations, I need to style the pins with three different colors.

Now I'm confused about the relationship between layers and styles. It seems that pin colors are defined for each individual layer, so to create the map I want, I need three layers--one for each pin color.

But when I create a feature on an individual layer, the templates for all layers appear in the Editor (see screenshot Editor-1.png).

Earlier today, I could select a feature, and it would appear three times in the Editor pane. But now I can no longer select features, and I don't know why.

Can someone explain the relationship between layers and styles? How many layers do I need to have three different pin colors?

[AndyKubrin]

Now I can select features again, and when I do, the feature appears three times in the Editor pane, once for each layer style. (See Editor-2 screenshot.) Why would that be?

If I delete one, all three go away.

[MaazaMekuria]

@AndyKubrin I think you would need perhaps a category key field in your layer that allows you to classify the features you want to style accordingly to different colors and use only one style to render the layer.  You don't need three layers divided by color scheme if you have a category such as a value difference or label that you can use to apply a style schema.  Styles—ArcGIS Pro | Documentation is the documentation that would be helpful. 

You may also create three separate layers and style each layer separately  but that is unnecessary if there is  a category field that allows you to set class of items that are to be rendered separately.  

[AndyKubrin]

@MaazaMekuria what you're proposing makes sense. I can't figure out how to create a category key field in the layer, though. 

These instructions look promising, except that when I access the Fields pane, there's no option to add a field. All I can do there is manage the display names of existing fields. (See attached screenshot.)

How do I add a field? I created the Site field shown in the screenshot, but now I don't know how, and I can't find my way back to that UI.

Can you help? Thanks!