onSecondary

accentIconTheme

This property had only been used to configure the color of icons
within a FloatingActionButton. It’s now possible to configure the icon
color directly or with the FloatingActionButtonThemeData. See
FloatingActionButton and ThemeData’s accent properties.

Timeline

Landed in version: 2.3.0-0.1.pre
In stable release: 2.5

References

API documentation:

ColorScheme

FloatingActionButton

FloatingActionButtonThemeData

TextStyle

TextTheme

Theme

ThemeData

Relevant issues:

Issue #56918

Relevant PRs:

PR #81336

Other:

Material Theme System Updates