Target Reticle - Do you remember this old UI feature? Or was it an addon?

Ok y’all this has been driving me crazy since returning to WoW a few weeks ago.

In current WoW live, when you target an ally there is a green reticle Under them. When you target an enemy there is a red reticle under them.

When I used to play, there was an option to make this reticle WAY more opaque and visible… like so colorful and you couldn’t miss it. In fact it would even override negative ground particles when turned all the way up.

Does anyone remember this feature, and was it an in game feature or add on feature?