Better default syntax colors

[sharpchen]

PR Summary

1. String: DarkCyan -> Green, as green is more intuitive color for string
2. Keyword: Green -> Magenta, as keyword is not string
3. Type: Gray -> Cyan, make it colorful
4. Operator: DarkGray -> Cyan, as Operator are generally not right next to Type
5. Command: Yellow -> Blue, as main color of pwsh icon is blue
6. Number: White -> Yellow, number should be distinct from the default symbol interpretation(into string)
7. Parameter: DarkGray -> Magenta, make it distinct, related: Predictive text implementation is terrible #5169

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After:

PR Checklist

• PR has a meaningful title
  • Use the present tense and imperative mood when describing your changes
• Summarized changes
• Make sure you've added one or more new tests
• Make sure you've tested these changes in terminals that PowerShell is commonly used in (i.e. conhost.exe, Windows Terminal, Visual Studio Code Integrated Terminal, etc.)
• User-facing changes
  • Not Applicable
  • OR
  • Documentation needed at PowerShell-Docs
    • Doc Issue filed:

Microsoft Reviewers: Open in CodeFlow