editor.tokenColorCustomizations not working (overriding github light in settings.json)

[mkarikom]

How to reproduce:

Please see attached settings.json.zip to reproduce.

Expected Behavior

editor.findMatchHighlightBackground should be close to magenta (#ff54f6 40% opacity), as specified by (#ff54f666) below:

    "editor.tokenColorCustomizations": {
        "editor.findMatchBackground"          : "#ff54f633",
        "editor.findMatchHighlightBackground" : "#ff54f666",

Observed Behavior:

As shown in the screenshot (after Developer: Reload Window), the editor.selectionBackground is still the default light theme (#ffdf5d 40% opacity).