Color Scheme: Differentiate parameter reference and parameter assignment

[tolotrasamuel]

Thanks for the feedback! If your issue is related to the Flutter framework itself,
please open an issue at
github.com/flutter/flutter.

Steps to Reproduce

Please see here:
user (parameter name) and user (parameter value) are the same color (both white).

It would be convenient if we distinguish them with a different color.
So I tried to modify the color scheme

But unfortunately, it changed both at the same time

Version info

Doctor summary (to see all details, run flutter doctor -v):
[√] Flutter (Channel stable, v1.12.13+hotfix.8, on Microsoft Windows [Version 10.0.18362.836], locale en-MU)

[!] Android toolchain - develop for Android devices (Android SDK version 28.0.3)
! Some Android licenses not accepted. To resolve this, run: flutter doctor --android-licenses
[√] Android Studio (version 3.6)
[√] VS Code (version 1.43.2)
[!] Connected device
! No devices available

[stevemessick]

@stereotype441 Should this be moved to the sdk repo? Seems more like a change in the analyzer.