If a Color3 property is selected in the Properties pane then the color does not change when a different object is selected in the Explorer pane. If the property is deselected in the Properties pane, then it’ll apply the new color to the newly selected object.
Here’s a gif/gfy.
The mouse is a bit off in the video, but it should still be easily understood. First I show how the too GUI objects’ BorderColor3’s are different, then I select the blue BorderColor3 in Properties and show how once a Color3 propert is selected it will not update when new objects are selected.
This may be a duplicate, but I feel it deserves more attention since it’s been around for more than 8 months unsolved.