Use syntax + scope with background color

[cbancestry]

Seems like you could get the best of both worlds by highlighting scope using background color and maintaining syntax highlighting.

[katspaugh]

Indeed! However, background might be a bit annoying. One could have the same basic color for identifiers, but with different luminosity. Like, the deeper is the callback hell, the darker is the color. Or lighter, if the background is white.

[MattiSG]

+1, this is clearly how I have had this in mind for months.