How to manage custom colors?

As we love Flutter to develop any kind of custom and beautiful UI. Sometimes while developing awesome UI, we have to use custom colors and we end up putting custom `const Color(0xFF______) `all over the code.

1. No need to manage
2. We should manage Colors somewhere specific like we do in Android
3. Something Else ?

The issue names no files, tests, or entry points; begin by reviewing the Flutter template's existing custom-color usage and the issue discussion. Done requires choosing and documenting a single color-management approach for the template, with its scope and expected usage made unambiguous.

Written by the indexing model from the issue text.