dotnet-outdated is a tool to check for outdated .NET Core dependencies.
Add DotNetOutdated as DotNetCliToolReference to your .csproj file:
<DotNetCliToolReference Include="DotNetOutdated" Version="x.x.x" />
dotnet outdated
Yellow is for non-major version available to update. It's generally safe to update so you should do it.
Red is for new MAJOR update which may possible break something in your code. You should read the docs before updating.