Better late then never, since i was having the same problem with the same files i was looking for a solution as well.
What i did was install the Material Theme. It's a beautiful theme for JetBrains tools and it comes with new icons for file types. You can install this theme like any other in the preferences panel under plugins.
Example:
Two of these are SASS files, two are Blade templates. File type icons look almost exactly the same.
Unfortunately, you can't. Please vote: https://youtrack.jetbrains.com/issue/IDEABKL-835
You can use File Colors to color the editor tab instead (based on the custom scope) -- fully working solution if you need it now:
Better late then never, since i was having the same problem with the same files i was looking for a solution as well.
What i did was install the Material Theme. It's a beautiful theme for JetBrains tools and it comes with new icons for file types.
You can install this theme like any other in the preferences panel under plugins.