vscode - change highlight color of current file

Question

How can I add a custom style for the background of the opened file (the pale-grey behind fetch.js):

Answer 1

I believe you are looking for the list.inactiveSelectionBackground theme setting. You can set this using workbench.colorCustomizations

"workbench.colorCustomizations": {
    "list.inactiveSelectionBackground": "#f0f"
}

This color used used when the explorer is not focused. Use list.activeSelectionBackground for when the explorer is focused

Answer 2

To highlight the current file tab on top -

Under Settings --> "workbench.colorCustomizations", add some colors to the tab border and/or to the tab background:

"tab.activeBorder": "#ff0000",
"tab.unfocusedActiveBorder": "#000000",
"tab.activeBackground": "#4a4a75",
"tab.unfocusedactiveBackground": "#000000"