The "OmniSharp server is running" icon isn't compatible with most light themes.

## Issue Description ##
The "OmniSharp server is running" icon isn't compatible with most light themes. It's always white which is hard too see.

## Steps to Reproduce ##
It's always behave like that.

## Expected Behavior ##
Should adjust color to themes.

## Actual Behavior ##

## Logs ##

### OmniSharp log ###
Post the output from Output-->OmniSharp log here

### C# log ###
Post the output from Output-->C# here

## Environment information ##

**VSCode version**: 1.43.0
**C# Extension**: 1.21.14

Dotnet Information
.NET Core SDK (reflecting any global.json):
Version: 3.1.101
Commit: b377529961

Runtime Environment:
OS Name: Windows
OS Version: 10.0.18363
OS Platform: Windows
RID: win10-x64
Base Path: C:\Program Files\dotnet\sdk\3.1.101\

Host (useful for support):
Version: 3.1.1
Commit: a1388f194c

.NET Core SDKs installed:
3.1.101 [C:\Program Files\dotnet\sdk]

.NET Core runtimes installed:
Microsoft.AspNetCore.All 2.1.15 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.App 2.1.15 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 3.1.1 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.NETCore.App 2.1.15 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 3.1.1 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.WindowsDesktop.App 3.1.1 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

To install additional .NET Core runtimes or SDKs:
https://aka.ms/dotnet-download

Visual Studio Code Extensions

|Extension|Author|Version|
|---|---|---|
|csharp|ms-dotnettools|1.21.14|
|python|ms-python|2020.2.64397|
|unity-code-snippets|kleber-swf|1.3.0|
|unity-tools|Tobiah|1.2.3|
|vscode-theme-github-light|Hyzeta|7.10.1|;